A mysterious disease known as 'the gloom' is sweeping through the city, and tensions are high as a rebellion brews. But Garrett, the master thief, soon figures out he isn't the only thing that lurks in the shadows. "Thief" takes place in a dark fantasy world inspired by Victorian, gothic, and steampunk aesthetics. Garrett, a master thief who has been away from his hometown for a long time, returns to it, a place known only as The City, and finds it ruled with an iron grip by a tyrant called The Baron. While The City is ravaged by a plague, the rich continue to live in isolation and good fortune while the poor are forming numerous mobs against the authorities, Garrett intends to use the volatile situation to his favor.
"Thief" begins when Garrett is paired with his former apprentice, Erin, who both ended up accepting the same job from their contact Basso. On their way there, Garrett steals Erin's claw without her noticing, because she usually uses it to kill guards when not necessary. They arrive at their job's location, Baron Northcrest's manor, and find a ritual taking place. Garrett gets a bad feeling and calls off the job, but Erin disagrees and she ends up falling into the center of the ritual, which was nearing its completion. Erin stops and floats in mid-air as she is surrounded by the ritual's energy. Garrett, while looking down at the light, has part of the stone that was used for the ritual embedded in his eye which then begins to glow and collapses.
After being uncounscious for a year, Garrett awakens and learns that the city is being plagued by a disease of unknown origin known as "The Gloom" and the Baron had put the city in lockdown because of it. Back to his hideout, Garrett is hired by Basso to steal a ring from a man named Cornelius who died recently, and sneaks into a foundry where the victims of the Gloom are being disposed. Just when Garrett grabs the ring, he is found by the Baron's right hand man, the Thief-Taker General, and flees. After completing the job, Garrett is introduced to Orion, a man who leads the resistance against the Baron's tyranny and hires him to infiltrate the "House of Blossoms" brothel in search for an ancient book. ...
Did You Know? Originally announced in 2009, under the working title "Thief 4." It was a revival of the cult classic "Thief" series of stealth games, which it was the fourth game.