⚠Outline is not the direction of the plot⚠
What is an outline?
An outline is a storyline that is almost completely narrative (everything is arranged according to the passage of time). It may affect the viewing experience and reduce the original foreshadowing, especially since the "Symptom" trilogy is based on suspense. In particular, Qian Luo's usual writing techniques are "flashback" and "flashback", and direct "narration" will lose a lot of suspense fragments.
But at some moments, the outline will not be directly narrative, because the simplicity and understanding of the outline is based on the story.
When Morrow Zhiyu was learning to walk, she frequently fell, resulting in photophobia, amblyopia, and heterochromia in her right eye. Folklore claims that heterochromatic eyes can see ghosts, and combined with her long hospital stays in childhood and her introverted nature, other children in kindergarten avoided befriending her. Even in elementary school, despite her excellent academic performance, her introversion and lack of friends made her a target of bullying. This left her with severe psychological trauma and depression. During this period, her parents, preoccupied with their work, were unaware of what she was going through and neglected her care.
One day, during an episode of bullying, she was “rescued” by a senior student, Ruidong Mo. Ruidong, a junior high schooler, also endured bullying due to a birthmark resembling a flower that covered half his face. The two became close friends, bonding over their shared struggles. Morrow’s high intelligence allowed her to engage in meaningful conversations with the older Ruidong.
One day, Ruidong invited Morrow out and confided in her about his parents' indifference, lamenting that they had even forgotten his birthday. As they crossed the crosswalk, Morrow realized she had dropped her wristband—the one she used to hide her scars from self-harm and suicide attempts—on the opposite side. She ran back to retrieve it. Ruidong, following her, was hit and killed by a drunk driver. His final words to Morrow were to close her eyes, stay on the crosswalk, and quickly head toward a crowded place.
The driver, a wealthy and influential individual, avoided legal repercussions by paying millions to Ruidong’s parents as hush money, turning the incident into a fabricated “suicide by jumping.” Witnessing her friend’s death shattered Morrow’s psyche, leading to PTSD that compartmentalized the memory. This resulted in hippocampal abnormalities causing chronic depression, anxiety, and anorexia. Additionally, the compounded traumas of her youth gave her dissociative identity disorder, though the alternate personalities rarely surfaced.
By junior high, Ruidong’s younger sister, Summer, began investigating her brother’s death for unknown reasons. Hiring Luo Zheng Xuanqing, she discovered that Morrow was the key witness, though too young at the time to testify. Now of age, Summer approached Morrow. However, the encounter triggered intense PTSD, leaving Morrow sleepless and distressed. Following advice from her guardian, “Anna,” she resumed medication and sought hypnotherapy and psychological counseling under Dr. Ann. To protect herself, Morrow’s brain completely suppressed all subconscious memories of the “car accident.” As treatment progressed, Morrow began to loathe her memories, ultimately dissociating from them entirely.
A new personality, Xiaozhi, emerged without any recollection of Morrow’s experiences. During this time, Xiaozhi met “Moru,” a blind boy with disabled legs. One day, Xiaozhi, influenced by an alternate personality referred to as “Auntie,” ventured out to find a “doctor” and encountered Luo Zheng Longlin. As Morrow’s childhood friend (though they attended different schools until junior high), Longlin found her behavior perplexing. When Xiaozhi was forcibly brought back, other personalities chastised her, hinting that the “doctor” was an enemy. After falling out with Moru, Xiaozhi unexpectedly gained permission to control the body again.
Xiaozhi’s lack of memories fueled her curiosity about “Mo Ruidong” and the “car accident.” Upon returning, she questioned whether the girl at the end of the hallway was part of herself and demanded the return of her memories. The girl was shocked and angered, warning Xiaozhi, “Memories are a curse. You had a chance for a new beginning, but you insist on inviting suffering.” She then integrated with Xiaozhi, marking the return of Morrow as the primary identity.
Upon returning, Morrow was disheartened by her actions, continuing to despise her memories for causing her mental illnesses and avoiding Moru for reasons she couldn’t comprehend. During a period of despair, Longlin convinced her to delay her suicidal thoughts. In a session with Dr. Ann, Morrow described her personalities, referring to one as the “doctor” and expressing her dislike for him. Dr. Ann briefly left the room. During his absence, Morrow found an old photo in his cluttered belongings depicting a boy with brown hair and a girl with black hair. When Dr. Ann returned, he seemed shorter, and his counseling turned “invasive.” Suspicious, Morrow resisted his hypnotic attempts.
Later, Anna arrived and took Morrow away, but her height and lighter eye color raised alarms. With Luo Zheng Xuanqing’s encouragement, Morrow finally confronted the importance of her memories, accepting that they couldn’t be changed. Determined to assist in uncovering the truth, she suddenly found herself held hostage by Anna, who put a knife to her neck. Xuanqing burst in with a gun, creating a tense standoff.
Xuanqing recorded everything, warning Anna not to act recklessly. Anna claimed, “Though a mentally ill person can’t testify, they can confess.” She hypnotized Morrow, coercing her to say, “I pushed Mo Ruidong off the building.” However, Rui’en, a subconscious entity, intervened in Morrow’s dream. He thanked her for enduring as the “final piece of evidence” and having the courage not to take her own life. Believing Morrow was ready to reclaim her memories, Rui’en guided her to say, “I will tell everything I know.” Sacrificing his own “existence,” Rui’en restored Morrow’s memories.
As the traumatic memories resurfaced, Moru transformed into Mo Ruidong’s likeness. With a clear mind, Morrow recounted the TV show airing on the night of the incident, the temperature, the date, the route, and the scene. As she recovered, Anna’s hypnosis failed entirely. Enraged, Anna insulted Mo Ruidong and attempted to end it all by dragging Morrow toward a window for a fatal leap. Morrow managed to knock the knife from her hand, giving Xuanqing a chance to fire a tranquilizer gun.
Anna was arrested for assault, but the case of Mo Ruidong’s death remained under appeal.
(Note: The real culprit is Dr. Ann. Multiple hints throughout the story reveal this, such as the horizontally flipped memory and the tattoo seen on the “wrong” hand. Dr. Ann and Anna are fraternal twins; Ann has brown hair and green eyes, while Anna has black hair and black eyes. Dr. Ann manipulated Anna through psychological control, having her both frame herself and subtly influence Morrow’s perception of her “memories.” Although Anna is in custody by the end, Morrow continues to harbor doubts.)
Hugh Xin is a boy suffering from multiple chronic illnesses. Raised in hospitals, he considers himself incapable of understanding "normal" people, feeling a vast chasm separates him from them. After his close cousin, Elynne Xia, passed away, and all the other children he knew in the hospital also succumbed to their illnesses, he left his hometown to return to a place he once lived as a child. (He ends up attending the same high school as Morrow Zhiyu, Summer Xia, and Lorrin Yuezheng.)
Hugh is not good at expressing himself and is overly timid. This led him to miss the chance to say a final word to his cousin before her death. After a chance encounter with Morrow, who was "researching a murder case," he later met Lorrin Yuezheng. Lorrin claimed he could help Hugh see Elynne again, provided Hugh followed the address and time on a piece of paper he gave him.
Hugh repeatedly waited at the address written on the paper, but almost every time, he only saw Summer Xia. Occasionally, he caught a glimpse of Lorrin, but he could never get close enough to him. Despite the oddness of these encounters, Hugh and Summer grew familiar with each other. One day, Hugh came across Summer crying. Confused, he questioned what someone "healthy and normal" could possibly have to be so upset about. “What’s there to despair over if your body doesn’t hurt and you’re alive?” he asked. Summer snapped back, “What’s the difference between losing a whole negative number all at once and having countless small negative numbers pile up and then subtracting them? (Having bad health is a huge burden, but I have countless small burdens stacked up too, and I’ve reached my breaking point. Is that not allowed?)”
This sparked a heated argument. Hugh, prone to outbursts due to his experiences with seemingly "healthy" people overshadowing those who truly needed help, said hurtful things. The two parted on bad terms.
Hugh never saw Summer again afterward but deeply reflected on his words. He believed someone as kind-hearted as Summer wouldn’t have said what she did without a reason. Although he wanted to apologize, he lacked a clear plan or action to do so. A few weeks later, he suddenly learned that Summer had jumped to her death the day before. He also noticed the time indicated on Lorrin’s paper no longer extended beyond Summer’s death. Feeling devastated, he returned to where he had met Morrow.
Morrow, grief-stricken, told Hugh that Summer’s family didn’t care about her. "Her death means no more to them than her brother Mo Winter's did. As long as she didn’t bring home millions, they couldn’t care less,” she said, listing absurd and cruel things her family had done. Morrow lamented that Summer’s death was unfair.
Hearing this, Hugh felt inhuman for the cruel words he had said during their argument. In his stress, he accidentally broke a keepsake from another friend who had passed away. Plunged into guilt over his lost friends, Hugh quickly spiraled into believing he had caused Summer’s death and, overwhelmed by his conscience, took his own life.
However, Hugh inexplicably woke up the "day before" his death and even dreamed of an orange-haired boy (who seemed mildly annoyed) alongside a girl yelling at him for being brainless. To his shock, everything around him was identical to the day before, except the broken keepsake had completely disappeared. Hugh believed his late friend had miraculously returned to protect him.
He sought out Morrow, explaining Summer’s impending death that evening. Morrow dismissed him as crazy. When Hugh tried to find Summer himself, his legs dislocated due to his condition, leaving him immobilized. Clinging to a shred of hope, he later received a message from Morrow: “She sent me a suicide note, along with the location where she plans to jump.” After that, Morrow stopped responding. In a panic, Hugh once again lost another keepsake after midnight, only to wake up the next day in a repeat of events.
This time, Hugh didn’t directly try to convince Morrow. Instead, after school, he told her, “If Summer sends you anything, give me her address.” With this information, Hugh successfully found Summer. However, she was in a state of despair and unable to listen to him, still hurt by the things he said weeks ago. Before Morrow could arrive, Summer jumped again.
Hugh returned more self-reproachful than ever. Staring at all the keepsakes of his cherished friends, he realized that discarding all of them might allow him to return to the day of their argument. After a painful struggle, he concluded: "They wouldn’t want me trapped by the symbols of their deaths. I must let go of a death caused by me, just as I have failed every one of them.” Reluctantly, he abandoned everything except Elynne’s keepsake.
However, by the time Hugh decided, it was past midnight, and he had no choice but to give up Elynne’s keepsake too. “I’m not letting go because I’ve forgotten you or them. You will all become part of who I am. I will remember and carry forward your will. Your deaths will no longer signify my destruction... but rebirth from the ruins.”
When he next encountered Summer, Hugh prepared countless words but remained silent, fearing his awkwardness would worsen things. Instead, he returned to the spot where she had jumped and managed to grab her as she fell. Even as his right arm dislocated, tearing down to the muscle, he refused to let go. Hearing his ligament snap, Summer looked at him in shock, and Hugh told her, “I don’t know how terrible your family is, but you’re worth a hundred times more than they are. There’s someone who cares about you a thousand times more than they do (referring to Morrow).” Summer stopped struggling, and together, they held on until Morrow arrived to help.
Though Hugh’s keepsakes never returned, he became friends with Morrow (and by extension, Lorrin). One day, Hugh asked Lorrin why he had only encountered Summer each time. Lorrin replied with a question: “If someone truly had divine power, could they see every truth beyond this world?” He admitted he couldn’t help Hugh find Elynne again but cryptically added that if everything proceeded as planned, Hugh might one day make a reasonable wish.
(Note: Summer Xia had two older brothers. The second eldest, Mo Winter, also died. The eldest was a genius, leading their family to adopt an indifferent attitude toward the other children as long as they simply stayed alive.)
When Summer Xia, unwilling to accept her placement, was reassigned to the advanced class, all class president duties fell upon Lorrin Yuezheng, the vice president. With the added pressures of class evaluations and truancy issues involving Gray Yan, Lorrin found himself overwhelmed. Gray's neutral-sounding name, androgynous appearance, and the fact that no one in the class had spoken to him further complicated matters, making it hard for Lorrin to learn anything about him.
One day, while working a part-time job, Lorrin unexpectedly spotted Gray in the crowd. Calling out to him multiple times yielded no response. Judging by his figure, Lorrin assumed he was male. However, when Lorrin finally caught up to him, Gray’s delicate, feminine voice left him stunned. After explaining the purpose of the pursuit, Gray agreed to "improve his attitude towards schoolwork" and even provided his home address for a potential home visit.
Despite this promise, Gray continued skipping classes and neglecting his homework. Left with no choice, Lorrin decided to visit his home. To his surprise, he was greeted at the door by someone who looked identical to Gray but had a different demeanor—this was Ken Yan, who introduced himself as Gray's twin brother. Ken, shirtless and with faint traces of an Adam’s apple, claimed to be assisting his sister. When Lorrin inquired about Gray’s whereabouts and mentioned homework, Ken directly handed over the completed assignments, suggesting, “Our handwriting and knowledge are identical. You’re only chasing her because you have to, so let’s just help each other out.”
Curious about the siblings’ dynamic, Lorrin pressed further. Ken revealed their precarious situation: neither of them had legal identification. Due to their striking resemblance, Ken would occasionally attend school in place of Gray. To avoid exposure, the siblings ensured they were never seen together. Ken admitted to avoiding classes for fear of being questioned, which might unravel their secret. When Lorrin brought up their differing voices, Ken explained, "I don’t talk to others—it avoids trouble. I don’t have friends because I can’t risk anyone blabbing about my status."
Seeing the root of their anxiety and apathy toward school, Lorrin began waiting for Gray/Ken outside their house each morning, walking them to school and introducing them to his trusted friends: Morrow Zhiyu, Summer Xia, and Xīnsù. Having explained the situation in private, Lorrin ensured that his friends were supportive and discreet. When others tried to talk to Gray/Ken, even the typically reserved Xīnsù would step in to deflect attention, helping the siblings feel more secure. Gradually, Gray/Ken, moved by the group’s sincerity, committed to attending school regularly and completing their assignments.
Though Lorrin’s initial focus was the class evaluation, he and his friends eventually developed a close bond with Gray/Ken. This connection led to uncovering critical details about the tragedy surrounding Summer’s brother, Winter Xia, which exonerated Anna from suspicion. However, due to the limited resources of a police officer tied by familial obligations to the culprit, gathering sufficient evidence before the case expired by year-end became a daunting task. Everyone agreed that extracting a confession from the perpetrator was the only viable solution. Gray/Ken’s imaginative ideas greatly contributed to the planning, though their seamless handoffs of plans and recollections sparked subtle suspicions among the group about their true identity. These suspicions, however, remained unspoken.
One day, Lorrin encountered a boy who introduced himself as “Qingji.” The encounter initially felt surreal, as if he were hallucinating from delving too deeply into supernatural matters. Qingji claimed to know Lorrin’s doubts about achieving a just outcome in the case and offered a solution: reveal Gray’s secret—that Gray and Ken were one and the same. To entice Lorrin further, Qingji promised to reunite Xīnsù with her cousin and even reconcile Lorrin’s estranged parents. Demonstrating his mysterious abilities, Qingji left Lorrin with the choice to decide.
Torn by the decision, Lorrin sought advice from Hugh, asking, “If you could reunite with your cousin but at the cost of a friend’s sacrifice, would you?” Hugh sighed deeply and countered, “What will the cost be this time? Will we still be left with empty hands?” The conversation ended there. Resolving to speak with Gray directly, Lorrin confronted them, asking, “You and Ken are the same person, aren’t you?” Gray was shocked, fleeing in panic—a clear sign of a distress attack.
Despite numerous attempts to reach out, Gray stopped coming to school. One day, while passing by Gray’s house, Lorrin encountered Ken, who let him in after hearing his sincere explanation. Ken’s first words were an apology: “I don’t know why I acted like that… but I can’t face any of you—or myself.” Exhibiting severe psychosomatic symptoms, Ken spoke of potentially moving away. With Lorrin’s encouragement, Ken began recounting their past: during prenatal checks, they were thought to be normal twins. However, at birth, it was discovered that Gray’s upper body emerged from Ken’s malformed lower body, sharing a pelvis. A compensation settlement followed the medical oversight, and after surgery, the conjoined twins survived, resulting in Ken’s upper body and Gray’s lower body comprising one being.
Raised as a girl due to their anatomy, Ken later identified as male during adolescence but struggled with identity, creating the personas of Gray and Ken to reconcile his existence. “Neither of them really exists,” he admitted. “They aren’t even full personalities. If I had dissociative identity disorder, at least it’d feel like they were real… but they’re just lies. Lies that feel more real than just being me.”
Lorrin, understanding the depth of Ken’s struggle, shared his own: born a boy but named “Linglong” under the false promise of uniting his parents, he too grappled with identity. “Your body isn’t something you chose. Neither is your past. You don’t owe anyone an explanation, least of all me. Just know this: you’re my friend, no matter what you call yourself.”
The next day, Ken waited for Lorrin at his door. It was the last day of school before the holidays, and on their way home, the group encountered Qingqing Lezheng. Though the evidence they had was solid, bureaucratic delays meant the case would only proceed after the statute of limitations expired, allowing the culprit to go free. Anna might even remain the scapegoat. Despite their disappointment, Summer and Morrow could only smile wryly at the futility of their efforts, silently acknowledging that in the grand scheme of things, they were just small players in a vast and indifferent world.
Because all five individuals had achieved "narrative significance" (a beginning, a climax, and a changed conclusion), and their endings were deeply tragic (in the sense that, despite each person experiencing significant growth, none of the major issues they faced at the start of their stories were resolved—those problems remained, continuing to weigh on them negatively and being largely dismissed by others), they came to realize their own insignificance. They understood that the events in their lives were unlikely to lead to any satisfying resolution.
Qinglin and Qingji, recognizing that this timeline had reached its most tragic point, arrived to invite these five fragments of tragedy to return to their origin.
However, all five fragments expressed that, despite their tragedies, they no longer wanted to die. Qinglin and Qingji agreed that after the five had passed away, they would extract them from this timeline to prevent the continuation of their tragic cycle. They also offered to answer Lorrin Yuezheng's lingering questions: "Are there more worlds beyond this one? More universes beyond this universe? Is the world I know just one layer beneath the worlds you traverse?"
The answer was affirmative: "Yes. At its most fundamental level, everything consists of existence and meaning itself. Logically speaking, the lowest-level world we recognize is the world itself." Lorrin acknowledged this response and declared his work complete.
Qinglin and Qingji were intrigued by the five children’s struggles with "selfhood," and this curiosity led them to reflect on their own origins (at the time, Qinglin and Qingji had no memory of their identities). In the eyes of the five, it seemed as if they regained all their memories in an instant. Recognizing the artistry within each individual, they granted all of them additional redemption by inviting them into an artistic dimension.
The fact that Lena Yue, the young lady born into a semi-aristocratic family, would frequent a place like a bar—a setting most would deem “improper”—was surprising. While she wasn’t a heavy drinker, her habit of visiting a bar at least once a week and consuming a low-alcohol fruit wine was enough to draw criticism, especially for someone who had just turned 19. Lena’s initial visit to a bar was merely a sightseeing check-in, but she soon began frequenting a bar near her home.What drew her attention repeatedly was the resident band playing there. Being born into a family of musicians, Lena appreciated their compositions, which reflected a decent level of aesthetic taste, though the band's overall performance was quite average. At first, Lena attended only as a listener, until one day a drunk man harassed her, and Xarrin Zhang, the band’s bassist, stepped in to help her out. In return, Lena corrected Xarrin’s bass posture—he had been holding it like an electric guitar—and made subtle yet significant adjustments to several conflicting notes in the sheet music. It was then she learned that Xarrin was the composer of the pieces. Due to the loud environment of the bar, where low-frequency sounds were barely audible, he not only wrote basslines carelessly but also rarely played them properly.
As a wealthy young lady, Lena sponsored better sound equipment for the band and started teaching Xarrin how to write proper basslines. She also discovered that Xarrin lived in poverty and soon noticed that his mental and emotional state could hardly be described as stable. Xarrin’s circumstances awakened Lena’s protective instincts, and the two gradually grew closer. Initially wary, Xarrin found himself relying on Lena due to his deep-seated need for care.Lena eventually learned about Xarrin’s past: his parents had divorced, and while he had an older sister, he currently lived alone. Lena once visited his home and was shocked by the mess and squalor. She tried to find better jobs for Xarrin, but he consistently turned them down. Lena assumed he was simply a freelance artist and didn’t suspect otherwise.
Being the youngest of three children in her family, Lena had always been treated as a “decorative vase” by her parents. In their eyes, she was only meant to be an obedient vessel—greeting elders politely, comforting her family when they were tired, happily volunteering, and occasionally crying over small frustrations only to be soothed into laughter again. It was as if her sole purpose was to charm everyone around her.After a heated argument with her family over her refusal to inherit her uncle’s role as a conductor, Lena left home in anger. Considering that her “friends” and “relatives” might reveal her whereabouts, she sought refuge at Xarrin’s place. Despite their ambiguous yet obvious mutual affection, the two did not officially confirm their relationship during this period of cohabitation.However, Lena, having been pampered her entire life, found herself unable to adapt to Xarrin’s lifestyle. His habits—barely eating proper meals, leaving things in disarray, keeping the lights off at night, drastically reducing his sleep, and his inexplicable refusal of better accommodations and jobs Lena introduced—left her frustrated. They frequently argued, but these disputes often ended with Xarrin abruptly going silent.
“He suddenly stops talking, like this, every time,” Lena thought, feeling exasperated. “It’s like a fishbone stuck in your throat. Just say something—if you have a reason, tell me! How am I supposed to know what you’re thinking if you don’t say anything?” Yet, caught in her anger, she would slam the door without uttering another word. By the next day, Xarrin’s attitude would return to normal, and Lena’s softened heart would allow their strange cohabitation to continue.One day, while sorting through some clutter, Lena stumbled upon a notice from Xarrin’s high school urging him to continue his first-year studies. From this, Lena deduced that Xarrin was only 14 or 15 years old—the typical age for a high school freshman. Although she wasn’t sure how a minor could enter a bar, she knew that dating an underage person was a crime. Overcome with anxiety about her actions, Lena immediately left Xarrin.
She returned to her family, resigning herself to a stifling existence and refraining from making new friends. “Maybe my parents were right,” she thought. “I can’t control the outside world. I was so naive. The people I interacted with were far beyond my depth.”Though Lena and Xarrin ran into each other several times afterward, they pretended not to know each other, choosing to pass by as strangers. It wasn’t until Lena resumed her volunteer work that their paths crossed again. This time, a slightly indignant Xarrin muttered, “You’d rather help strangers than say goodbye to me when you left.”Deciding to end this doomed relationship, Lena advised, “You’re only 14. Focus on continuing your studies. You’ll be another year older in just a few days; if you don’t go back now, you’ll fall behind.” Xarrin, stunned by her words, replied, “I’m 17 now.”
Only then did Lena learn the truth about Xarrin’s family situation. His parents’ divorce had placed him and his sister in the custody of their wealthier but neglectful father. Their mother had remarried, and their father, preoccupied with his new family, gradually abandoned the siblings. Left to fend for themselves, Xarrin and his sister initially lived in their old home. However, his sister’s unfortunate circumstances forced her into an exploitative industry, and the chaotic environment drove a 13-year-old boy to move out on his own.A childhood friend helped him secure a tiny room to live in. Xarrin, wary of foster homes due to horror stories, didn’t dare seek help until he was on the brink of starvation. Even then, he discovered that the welfare system couldn’t take him in because his parents hadn’t formally relinquished custody.Xarrin had no idea where his parents were. Although his mother continued paying his school fees, he couldn’t locate her address, nor would he disturb her new life even if he could. To survive, Xarrin dropped out of school and took on various part-time jobs, fabricating his age to meet the requirements. He often faced eviction attempts by social workers enforcing the law, but these individuals offered no assistance in locating his parents. (A guardian is required to be present when a minor under the age of fourteen renews his ID card; a guardian is required to be present when a minor’s ID card expires. But he doesn’t know where his parents are, so his ID card keeps expiring, and he can’t do anything because of the expired ID card. He has to wait until he reaches adulthood to do anything.) He has been living on the edge of death for many years, but no one cares about him even after he dies (a guardian is required to be present when a minor’s body is burned into ashes; a guardian is required to pay for medical treatment for a minor). When Lena asked why he hadn’t told her the truth, Xarrin responded, “I survive on lies. How could I show you my heart from the start?”
After some thought, Lena replied, “I’ll wait until you’re of age,” determined to avoid breaking the law or engaging in a romantic relationship with a minor.In the novel’s conclusion, Xarrin self-deprecatingly remarked, “The concept of love can emerge overnight, just as becoming a legal person happens in an instant. No one condemns those unworthy of being called human who are shielded by the law, nor do they pity those left unprotected by it.”As the story ended, “The child crowned with laurels bid farewell, while the child beneath the toxic cassia trees paced toward tomorrow.”
(Note: Laurels symbolize honor, while cassia trees, though similar in appearance, are highly toxic.)