A character in Babylon 5 who had an English accent and dies to save Susan Ivanova. I never really liked Marcus, and found him annoying and smarmy rather than witty and courageous.
Incidentally, in the credits of the final episode of Babylon 5, Sleeping in Light, every character is shown as they were in the beginning and as they were at the end. But, for Marcus' 'End' shot, there is a message saying that he is in suspended animation pending discovery of a new resucitation technology, by order of General Susan Ivanova.