Charles Marlow
Marlow's name may be inspired by the Elizabethan playwright Christopher Marlowe. Conrad's father was a translator of William Shakespeare who doubtless would have known of Marlowe's work as well. Some intertextual interpretations of "Heart of Darkness" have suggested that Marlowe's "The Tragical History of Doctor Faustus" may have influenced Conrad. Charles Marlow describes a character as a "papier-mache Mephistopheles", a reference to the Faust legend. Marlow's and Kurtz's journey up the Congo River in "Heart of Darkness" also has similarities to another work by Marlowe, "Dido, Queen of Carthage", in which Aeneas is stranded on the shore of Libya and meets the African queen Dido.
Gabriel Knight
All three games in the series focus on the adventures of Gabriel Knight, a New Orleans author and bookstore owner who finds that his destiny is to become a "Schattenjäger", or "Shadow Hunter". Gabriel's assistant, sidekick, and sometime romantic interest Grace Nakimura is a major supporting character in "Sins of the Fathers". In "The Beast Within" and "Blood of the Sacred, Blood of the Damned", she shares the role of protagonist with Gabriel. The player alternates between Gabriel and Grace for different portions of the latter two games.