The murderous members of an ancient sect will stop at nothing to get their hands on all Angel of Death paintings that exist. One such painting was displayed in the St. Petersburg Hermitage Museum, but it has been stolen and replaced with a forged copy. Agent Lara Svetlova is assigned to the case and her superiors enlist former art counterfeiter Maxim Durand to aid her. The duo will track down the thieves, an investigation which will take them throughout Europe.

Memento Mori is a conspiracy mystery adventure game. Both Lara and Maxim are playable intermittently. There are puzzles to solve, NPCs to meet and interrogate, objects to collect, and many locations to explore. Decisions made while playing influence the rest of the game and will result in one of eight different endings. Gameplay is point-and-click.