MacLeod is struck and "killed" by a speeding automobile. When he revives in the hospital, he attracts the attention of a deranged doctor, who kidnaps MacLeod for his research on a miracle cure for trauma. When MacLeod escapes from the doctor, the doctor murders a potential witness and frames MacLeod for it.

Seeking revenge for the apparent death of her lover, Walter Reinhardt, Rebecca Lord toys with MacLeod before she attempts to kill him with Reinhardt's sword. Rebecca knows nothing of Immortals or their combat, and she believes MacLeod murdered Reinhardt. Unbeknownst to her, Reinhardt is still alive, and is using Rebecca in a cat and mouse game to draw out MacLeod for their final confrontation.

Tessa witnesses the murder of a painter, Anne Wheeler, but the absence of a body leads everyone but MacLeod to doubt her story. MacLeod supports Tessa in her quest to obtain justice for Anne. It develops that Anne was killed by her Immortal ex-lover, to keep her from revealing his secret. After Tessa is taken to a police safe house, MacLeod realizes that the killer is in fact the Chief of Detectives, and he must rescue Tessa and bring justice to Anne's killer.

An Evil Immortal, Kuyler, has hired himself out down through time as an assassin -- the most successful killer in all of history. He strikes again in modern day Paris using his signature disguise as a mime. A French Police Detective, LeBrun, suspects that Duncan MacLeod is connected to Kuyler, but of course he cannot imagine that Kuyler once killed an eighteenth-century baron under MacLeod's protection. When LeBrun is wounded protecting Tessa from Kuyler's men, MacLeod confronts the Immortal assassin and puts an end to his centuries-old reign of terror.

Grace Chandel has been a Good Immortal, working for the betterment of mankind as a midwife, doctor, and scientist over the centuries. Her one weakness is another Immortal, Carlo Sendaro, a former lover who is obsessed with her and refuses to let her go. He slays Grace's current (mortal) lover and, when she refuses to run off with him, frames her for the killing. She turns to her old friend Duncan MacLeod for help.