The plot of Inqusition is set in the realities of 14th-century France. The player takes on the role of a young thief named Matthew, and his task is to find the legendary treasure of the Templars. On his way, there will be numerous difficulties in the form of clashes with the city guard, spies of the Grand Inquisitor and other opponents.

The story begins in Chatelet Prison, where the main character, Matthew, is serving his sentence. There he meets one of the Knights of the Templar Order named Jack, who soon dies under cruel torture. Before his death, the knight reveals to the protagonist the secret of the Templar treasure, thanks to which Matthew regains his will to live, decides to escape from prison and find the treasure.

The action takes place in a dozen or so diverse and extensive locations set in the realities of Paris at the end of the Middle Ages during the reign of Blackpox and the Holy Inquisition. During the adventure, we face difficulties in the form of battles with numerous opponents, roads full of traps, as well as a lot of puzzles and conversations with the characters we meet. The game exudes a dark atmosphere, thanks to dialogues stylized as speech from that era, graphics and suggestive, suspenseful music.