In the French wilderness, there is the fortress known as Masada. It's a base of preparation, where The Grail trains its elite soldiers for the inevitable day of Armageddon.

In Masada, Marseille is in charge. He is second-in-command to Starr, the Sacred Executioner of The Grail, and it is to Starr that he is ultimately loyal. When Allfather D'Aronique arrived at Masada to uncover Starr's conspiracy to control Jesse Custer, Marseille did his best to try and help Starr survive.

In the end, to escape both the Allfather and the unstoppable Saint Of Killers, his gambit was to hold The Messiah - a horribly inbred child who was the descendant of Jesus Christ - hostage at gunpoint. He was to have a helicopter and free passage out of Masada. In the end, however, both he and the Messiah were killed by the falling bulk of Allfather D'Aronique, who had been tipped out of his own helicopter by Starr.