This Can't Happen Here (1950)

Atka Natas is a secret agent from the oppressive regime of Liquidatzia. He visits his estranged wife Vera, a chemist who is involved with a group of exiles trying to smuggle their compatriots out of Liquidatzia. Almkvist, a local policeman and former lover of Vera's, contacts her while investigating the death of one of the refugees. Natas has a list of agents operating in the host country and wants to sell them to the Americans. However before he can do so, Vera tries to kill him, after an argument about getting her parents out of Liquidatzia.