He lived in the same village as Laurence, in a priory that later burned down and was used as UNIT HQ. Marcus found the Black Pyramid in Egypt, the prison of the Osiran Sutekh. Sutekth killed him but animated his corpse and used it as a vessel of his power. Scarman (or his body) returned home via a space-time corridor contained in an Egyptian sarcophagus.
He killed Ibrahim Namin, Sutekh's servant, and with a small number of Osiran service robots at his command set about doing Sutekth's will. He killed his brother Laurence, witnessed the destruction of the Osiran war missile, and travelled to the Pyramid of Mars with a possessed Fourth Doctor and Sarah Jane Smith to release Sutekh from the Eye of Horus. Despite Sutekh being freed, the Doctor defeated him, after which he relinquished his hold on Scarman's body, allowing him to die. Scarman appeared to regain personal consciousness in the moments before his death. (TV: Pyramids of Mars)