Marcus Cole, played by Jason Carter, is a fictional character in the universe of the science-fiction television series Babylon 5. He was a regular in the third and fourth seasons of the show. During his time on the series he was a leading member of the Rangers, a military force consisting of Humans and Minbari who served the "One", a triumvirate consisting of Jeffrey Sinclair / Valen, Delenn, and John Sheridan.