Highlander: The Raven

While on a security detail, Nick prevents the assassination of a politician. He is forced to shoot the would-be killer, who then falls to his death from atop a building, but when the assassin's body disappears, Nick suspects that he is an immortal. He asks for Amanda's help in tracking him down, but Amanda is hesitant to assist him, as she was friends with the immortal, Morgan Kenworth, in a past life.