The Man From U.N.C.L.E.

The Waverly Ring Affair (2x19)

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When secret "File 40" documents turn up outside headquarters, Waverly assigns Solo and Illya to find out if George Donnell is a double agent. Carla Drosten is too anxious to accuse Donnell and Solo must use special "Waverly rings" to try and expose the real double agent.