A series of bomb blasts at power plants draw Dr. Sam Waters and the task force to Pittsburgh, where Sam meets a charming bomb squad dismantler (guest star A. Martinez, ""LA Law""), and the flirtatious pair quickly form a romantic bond. Even so, their primary focus remains on targeting a deranged man (guest star Ron LaBelle), with an obsessive fetish for cleanliness, whose masterwork blast is timed to poison the city's water supply in just hours. Robert Davi co-stars.