The third game in Gabriel Knight series takes our hero Gabriel Knight, the former owner of a book store in New Orleans, and now a Schattenjäger ("shadow hunter") living in a castle in Bavaria, to Rennes-le-Chateau, a quiet town in Southern France. Gabriel and his assistant Grace Nakimura investigate the kidnapping of a baby: the son of Prince James of Albany was taken away, and the trace leads to Rennes-le-Chateau. While exploring the town and its surroundings and getting acquainted with the unusual history of the place, Gabriel and Grace realize supernatural beings are pulling the strings behind the scene, and get involved in a suspenseful mystery with a rich religious background.
"Blood of the Sacred, Blood of the Damned" is a 3D adventure game. Playing as Gabriel or Grace, you move through the fully 3D environment, which you can also view and explore from first-person perspective using the "camera" option. You interact with people and objects by clicking on them and then selecting one of the available actions. There are many kinds of puzzles in the game: traditional inventory-based ones, detective investigation, as well as complex puzzles based on your knowledge of the game's story.