The Time Tunnel - Season 1 - Eps 27: Merlin the Magician
Tony and Doug are frozen in time, then a rather fey Merlin appears in the Project base. He takes the guys out of time and freezes them, commands them to do his bidding, then sends them on to 544 A.D., Cornwall England. They meet a young pre-King Arthur while fighting Vikings and on Merlin's behest team up with Arthur. The Vikings apparently kill Doug and capture Tony and Arthur. Tony escapes with Arthur and Doug is rescued by Merlin and Guienvere. When the Project staff are ready to recover Doug and Tony, Merlin intervenes because he needs them where they are. Tony and Arthur get recaptured and so does Doug when he goes to help. Guinevere gets captured too. One of the Vikings kills Arthur and a ""detained"" Merlin shows up and reverses time to save him. The guys escape again and Doug gets reinforcements which Merlin disguises as Vikings while Arthur and Tony rescue Guinevere. Everything works out and Arthur and Guinevere are to be married.
About The Time Tunnel

Title: The Time Tunnel
First Air Date: 1966-09-09
Last Air Date: 1967-04-07
Status: Ended
Rating: 7.602/10 (from 171 votes)
Language: EN
Seasons: 2
Total Episodes: 30
Network: ABC
Genres: Action & Adventure, Sci-Fi & Fantasy, Drama
Production Companies: Irwin Allen Productions, 20th Century Fox Television, ABC, Kent Productions
Synopsis
The Time Tunnel is a 1966–1967 U.S. color science fiction TV series, written around a theme of time travel adventure. The show was creator-producer Irwin Allen's third science fiction television series, released by 20th Century Fox and broadcast on ABC. The show ran for one season of 30 episodes. Reruns are viewable on cable and by internet streaming. A pilot for a new series was produced in 2002, although it was not picked up.
Cast

James Darren
Tony Newman

Robert Colbert
Doug Phillipps

Whit Bissell
General Heywood Kirk

Lee Meriwether
Dr. Ann McGregor

John Zaremba
Dr. Raymond Swain