Voyage to the Bottom of the Sea (1964)

S1E12 No Way Out

Title: No Escape Plot: Nelson and Crane take on an undercover mission that puts their lives on the line to retrieve a Communist defector for the U.S. However, during the operation, the defector sustains injuries, and his beloved is left behind. He refuses to communicate with the agent stationed on Seaview—a secret double agent—until he can see Anna again. Yet, Anna's true nature is shrouded in mystery, and she may not be who she appears to be.