When a researcher with the Department of Defence is found dead, Nell must put her high IQ to the test when she goes undercover as his replacement; Hetty's ability to lead the team is questioned.
Illya and agent Mark Slate train a nightclub singer to impersonate a baroness working for THRUSH, but then the men from U.N.C.L.E. can't tell the two women apart.
The men from U.N.C.L.E. go on a swashbuckling adventure to rescue the princess of a tiny European kingdom from mobsters.
Solo, Illya and Mr. Waverly are held captive in the private torture chamber of a former THRUSH agent.