Before there was Sam Fisher, there was Garrett.
An orphan in a sprawling ancient city that teeters on the uneasy knife-edge of steampunk technology and magic, Garrett grew up on the streets picking pockets and cutting purses. One day, he tried to cut the purse of a Keeper.
The Keepers are a secretive organization that strive to maintain a balance of the various forces and factions, their own powers revolving around mysterious, powerful glyphs, and a jumbled series of prophecies foretelling what is to come. The Keepers have a substantial complex within the city, but it is guarded by their glyphs, and nobody ever notices that it is there.
Likewise, a skilled Keeper may pass unseen through a crowd, not invisible, but unnoticed. So, that Garrett saw the Keeper at all, let alone got close enough to try to snatch his purse, it was remarkable indeed.
The Keeper lured Garrett with the promise of a better life, and Garrett became an acolyte in the Keeper order.
There, he was trained, was subjected to the Keeper’s strict rules, learned little of their secrets, and heard much of their lies.
Garrett abandoned the Keepers and returned back to the streets, exercising his new skills as a professional thief. An amateur steals for themselves, a professional steals for another, and the decadent old city was full of intrigue, and jealousy, and all manner of things that people with money wanted for themselves, but that could not be bought.
Garrett delivered. When he was hired to acquire something through his network of fences and contacts, that thing softly vanished from its place. Walls and guards and locks and hiding places did not stop him.
He was, as some said, the greatest thief the city had never seen.