Portland detective Nick Burkhardt learns he is a Grimm, descended from a long line of warriors charged with protecting humanity from magical creatures known as Wesen, who are part human and part animal. a

Nick and Hank's investigation into a home invasion introduces them to a family with a barbaric background; Nick asks Monroe to protect Aunt Marie. 

A man puts the song `YMCA' on his speakers in a tram, which makes the other passengers dance inside. When everyone leaves the streetcar, the driver discovers a woman dead in the streetcar. 

When a young woman is found dead wearing nothing more than a nightgown, Nick is called to look into the suspicious circumstances, suspecting that this might be a murder. As the investigation goes on and he uncovers a string of female disappearances, Nick finds that he may be after a creature with hypnotic abilities that has a penchant for beautiful women. Elsewhere a reaper arrives in town looking to avenge the death of his friend. 

Hank and Nick are called to a high school to look into the gruesome death of a teacher. As the investigation continues all the evidence points to a troubled musical prodigy named Roddy. While Nick delves deeper into the mystery he recruits Monroe to try and speak with Roddy, to divert him off a path that would see him destroying his future for vengeance. Elsewhere Nick learns that his presence is affecting the creature world. 

A man is practicing with a `shake weight' but he accidentally throws it out of the window. When he goes to retrieve it, his house explodes. When Nick and Hank question him, Nick sees him do something very unusual.

A couple are walking through the woods when they're captured by a drug dealer. When he gets ready to kill them, he is murdered by a creature and they escape. 

A prison escapee from Hank's past returns on a quest for vengeance, leaving a trail of bodies in his wake. As the investigation continues, Nick comes to realise that this man is more than initially suspected and finds himself up against a rare and nearly unstoppable Wesen. After being battered in his own home and put in the hospital by his damage resistant foe, Nick turns to Monroe to end the violence and save Hank's life. 

Nick and Hank investigate the death of a man described by all as a `jerk' and in the process finds that two of the man's neighbours are Wesen. Juliette begins to worry as she notices several strangers taking pictures of her and Nick's house while elsewhere Monroe is beaten by Reapers for his assistance and friendship with Nick. 

When homeless people in Portland start to go missing, Nick discovers a black market supplying the wesen world with human organs. 

Nick and Hank track a deadly heartbreaker; Nick's growing recognition in the creature world becomes a threat to his and Juliette's safety. 

The investigation into a double homicide leads Nick to discover a fight club in the wesen community; Nick must draw on his inner strength to defend Monroe when he gets in trouble while helping out. 

When a botched robbery ends in murder, Nick and Hank must search for rare coins. Meanwhile,a friend of Aunt Marie's shows up with information about Nick's family. 

While investigating an arson-related homicide, Nick meets a mysterious woman. As he investigates he notices a striking similarity with the suspect and dragons of lore. Will he be able to avoid getting burned? 

Nick and Monroe investigate when a shop owner becomes the victim of a grisly murder; Nick thinks he has found an ally; Sgt. Wu becomes entangled in Adalind's plan. 

Nick tries to take Juliette on a romantic weekend but soon becomes embroiled in an unexpected case invovling a species of Wesen thought to be extinct. 

Nick discovers that Hank is seeing Adalind, the Hexenbiest who tried to kill Aunt Marie; Capt. Renard must act when a visitor threatens his position; Monroe and Rosalee help Hank and Sgt. Wu. 

Nick discovers that Monroe and Rosalee are harboring a murder suspect (Neil Hopkins) whose crime spree began overseas. 

An investigation into a construction worker's death leads Nick into a conflict in the creature world; Juliette makes Nick invite Monroe to dinner. 

A man involved in a Ponzi scheme commits suicide when the police arrives to arrest him. When they discover a woman caught up in the same scheme, Nick and Hank must save her from death. 

Juliette witnesses a murder committed by a creature who is unable to maintain his human form. Nick follows the leads and ultimately discovers that there may be more than one creature suffering from the same issue. 

A trail of murders reignites Nick's search for the gold coins; a mysterious woman in black starts to interfere with Nick and Hank's investigation; Nick's relationship with Juliette reaches a crossroads.