Mobster Jimmy Swain employs hitman Leonard Wynters, also known as "Captain Cold" for his weapon of choice, a nuclear-powered freeze ray, to eliminate his competitors and then the Flash.

Sam Scudder, a criminal mastermind who uses mirrors and holograms to commit his crimes, steals an advanced battery from S.T.A.R Labs East Coast division, which is then stolen from him by his partner, Stacia Masters, who flees to Central City and seduces her former classmate Barry into sheltering her at his apartment.