A man is found shot dead in a rundown Rockaway Beach house under a pile of money. Outside in his backyard is an ark that contains animals and eight people. The investigation reveals the man spread the belief that the world was ending and charged people to go on his ark where they would be saved. Back in the city, a man dressed as a giant cigarette, apparently protesting against a tobacco company, is found dead on the street. Stella reveals to Mac that she was possibly exposed to HIV at a previous crime scene.