Garrett has lived in The City all his life. He's an experienced and shadowy figure, skilled in thievery, stealth, infiltration and escape. He's known to the rest of the underworld as the ‘Master Thief' - the best of the best. His age is unknown.

Garrett has little memory of his parents, as they died when he was young. After he escaped the orphanage he was thrown into, Garrett's entry into the world of the thief was almost inevitable, yet his raw talent meant he quickly excelled. As well as his exceptional skills, Garrett relies on his in-depth knowledge of its streets, rooftops and shadows to get by.

Garrett is a self-reliant observer who sees more than others, and knows more than he lets on. His words often have gravitas but are balanced by a sometimes wry approach to life that offsets its darker edge (and Garrett's own.) Although Garrett once stole to live, now he lives to steal. It is less for the gold and more for the lure of the impenetrable, the impossible, the secret, the unknown. The challenge is what keeps his body and mind alive and sharp.

Garrett has a few rules he applies to himself; don't trust anyone, work alone and only kill as a last resort. Meeting a young thief on the streets of The City named Erin has challenged all three.

Garrett was born sometime before NRy812 in The City, at a young age his parents died (due to unknown circumstances) and Garrett was later turned over to a strict orphanage from which he eventually escaped and ended up living on the streets. His very survival depended on stealing, while he was still young he learned to swiftly relieve people of their possessions while they went about their daily business, leaving many to believe they had accidentally misplaced their belongings. For years he honed his thievery skills to perfection. Also learning to craft his own clothing, gear, and weaponry.

At some point after NRy830, Garrett moved into the abandoned Clock Tower located in the Stonemarket District. Though initially incomplete due to past fatal construction incidents, he effectively learned how to maintain the towers mechanisms. The ghost stories proved useful in keeping the locals from questioning his presence and allowed him to make it his safehouse.

As Garrett's reputation as a thief increased he eventually met Basso. Over time the two became close professional friends. Basso acted as his primary fence and gave him various jobs to steal certain valuables and objects of personal interest. Garrett also came to befriend Basso's magpie Jenivere, who acted as a courier between the two.

A few years prior to the events of the game Basso introduced Garrett to a young girl named Erin. It turned out she was the one who had tried and failed to pickpocket Garrett. Impressed by her talent Garrett personally took her on as his apprentice. Through the next couple of years he began teaching her the skills he had acquired and they developed a working partnership. However during a job to steal some paperwork for Basso, Garrett was spotted by a guard. Acting on impulse Erin killed the man. This reckless action horrified Garrett. He immediately told Erin they were through, that he had tried to get her to listen and was finished being responsible for cleaning up after her. 

Garrett could be considered a consummate professional. He is solely devoted to his profession, spending all his time and effort on larceny and honing his skills as a thief into an art. For Garrett, thievery is a form of freedom from the bonds of society and law. It is a central part of his identity; he steals because he's the best there is and he values his professional reputation. Garrett will often pass on jobs if they are too easy or do not involve proper thievery, while pursuing marks without commission if tempted with alluring challenge or reward. He views himself as a devoted thief and refuses to be something he perceives as lesser, be it an assassin or a grave robber. He finds needless death or collateral damage pragmatically abhorrent, viewing it as unprofessional and brings unneeded attention to his job.

Anytime he is not on a heist, he's planning the next one. What time Garrett uses for recreation he spends maintaining the clock tower he lives in as well as maintenance on his equipment. He also has both a personal and professional appreciation for fine art and craftsmanship. He is shown to collect rare and priceless items for his own personal collection, ranging from jewelry, paintings, or rare curios of unique historical significance.