Mister Marathon was a member of the Seven. and not much of his past is known. During the 9/11 crisis, Jack From Jupiter tried to flee, but Marathon convinced to let him stay. While carrying Mister Marathon due to his inability to fly, The Homelander wanted to abandon the mission but Marathon persuaded him to continue, by pointing out that Vought-American would fire them if they left. However, Homelander broke the plane when he was trying to slow it, killing Mister Marathon in the process. He was replaced by another speedster called A-Train.