1952. When an unsuspecting switchboard operator answers a mysterious call from a dying woman, she is entrusted with a top-secret message that pulls her into an international plot to destroy the world. Fast forward half an hour, Sheila is chasing friends, foes and old flames on the 14:52 to Exeter as members of the Nuclear Justice Association attempt to arm the entire world with enough weapons to destroy it. Can she, the not-so-innocent bystander, save the world? Or will her lack of experience and necessary skills drag the mismatched team down?