Troubled by nightmares in which he returns to his murderous ways, Angel (
David Boreanaz) learns that Detective Kate Lockley (Elisabeth Rohm) is hunting a serial killer with the same modus operandi he used to employ: the mark of the cross on the victim's left cheek. As it turns out, however, the killer is actually one of Angel's old cronies, a vampire named Penn (
Jeremy Renner). Still unaware of Angel's supernatural origins, Kate eventually cottons on to the nature of both her friend and her prey. She even suspects Angel of the murders until she does some research and learns that Penn has preyed upon Los Angeles before. Kate eventually ends up dusting Penn -- and promising Angel that she'll do the same the next time she sees him. Originally broadcast January 18, 2000, on the WB network, "Somnambulist" marked season one, episode 11 of the supernatural comedy drama. Beginning with this episode, Alexis Denisof is a member of the regular cast in his role as Wesley Wyndham-Pryce. ~ Brian J. Dillard, All Movie Guide