Napoleon Solo (Robert Vaughn) and Illya Kuryakin (David McCallum) are two members of U.N.C.L.E. -- a highly secretive international agency dedicated to maintaining order worldwide. When the two agents travel to Switzerland with the top secret combination to a vault containing nuclear weapons, Solo is kidnapped by a member of THRUSH, an evil rival organization, and replaced by an impostor. With the fate of the world at stake, Solo must attempt to escape from THRUSH headquarters.