In an episode filled with danger and compassion, Richie encounters Mikey, a huge Immortal of limited mental development and a fascination with trains. Richie takes Mikey home to MacLeod, who advises him that taking care of Mikey could be trouble. MacLeod remembers coming to the aid of a young Indian in trouble, when his help got the man killed. While MacLeod faces Tyler King, and Immortal who's coming after Mikey, Richie must find the maturity to take responsibility for Mikey's situation.