Voyage to the Bottom of the Sea - Season 4 - Eps 17: Nightmare
Poor Captain Crane. The things he had to go through. This time, he's in the Flying Sub, when he receives a distress call from the Seaview. He comes back to his sub, only to find it abandoned -- again. But wait, there's a force-field on the spiral stairs which knocks Crane out, and there's a stranger aboard who naturally shoots at him. Eventually Crane sees the crew, and he hears the voice of Nelson calling him a traitor. It takes about an hour, and a bullet in the shoulder (fired by guess who?), before Crane discovers aliens are testing the human race.
About Voyage to the Bottom of the Sea

Title: Voyage to the Bottom of the Sea
First Air Date: 1964-09-14
Last Air Date: 1968-03-31
Status: Ended
Rating: 7.7/10 (from 121 votes)
Language: EN
Seasons: 5
Total Episodes: 110
Network: ABC
Genres: Action & Adventure, Drama, Sci-Fi & Fantasy
Production Companies: Irwin Allen Productions, 20th Century Fox Television
Synopsis
Join the crew of the Seaview aboard their super high-tech submarine, where no mission is too dangerous and no threat is too deadly, be it enemy agents, mad scientists, deadly sea creatures, or impending nuclear disaster.
Cast

Richard Basehart
Adm. Harriman Nelson

David Hedison
Captain Crane

Terry Becker
Chief Sharkey

Del Monroe
Kowalski

Paul Trinka
Patterson

Richard Bull
Doctor

Robert Dowdell
Chip Morton