Coltec was a medicine man, shaman, and among the best of the Immortals, Coltec met a tragic end when he fell under the influence of a Dark Quickening and turned on his longtime friend, Duncan MacLeod.

Coltec, on his way to meet his friend in Seacouver, ran afoul of the evil Immortal Harry Kant as the latter was robbing a local grocer. Coltec challenged Kant and defeated him. This proved to be undoing, as killing Kant triggered a Dark Quickening, that quickly consumed the holy man. Taking the dead Immortal's leather jacket and handgun, Coltec calmly walked up to the grocer he had just rescued, and shot him in cold blood. He then hurried to his rendezvous with Duncan and Richie, but when the two walked up to greet him, he attacked without warning or challenge, assaulting MacLeod with a furious rain of blows.