Master thief Garrett is contacted by Keeper Artemus to steal two valuable artifacts. He soon learns that a Dark Age was foretold long ago and that an ancient book, the Compendium of Reproach, holds key information. As he investigates, Garrett realizes there is a traitor among the Keepers.

Thief: Deadly Shadows, the third entry in the series, focuses on stealth-based gameplay where shadows and sound are crucial to avoiding guards. Several mechanics are refined, and the major new feature is the non-linear exploration of the City, which allows side missions and affects Garrett’s reputation with different factions.