Solo goes to Sweden to obtain a new suspended animation device from Dr. A.C. Nilson, but the device and its inventor are taken by THRUSH. The doctor's daughter Neila helps Solo find him, and the doctor's assistant, Inga Anderson also feigns cooperation but is actually working for THRUSH agent Heinrich Beckmann. Beckmann uses the device to invade U.N.C.L.E.'s Scandinavian headquarters, and only Solo has a chance to stop him.
