With Spawn's help , Sam and Twitch surmise that Dr. Sarah Frost is the serial killer of the alley inhabitants. Spawn confronts her and witnesses her suicide by pesticides , a victim of her own imagined phobia. But when Sam examines Dr. Frost's body , he finds that now familiar symbol branded on her neck. Later , Sam and Twitch receive a cardboard box with a head in it and a cryptic message written on their office wall.
