Our time traveling heroes end up in the middle of the Siege of Khartoum, probably because Irwin Allen had access to stock footage from the movie "Khartoum". Coincidentally, there is also an alien invasion force there that plans to conquer the Earth by bombing London. The alien leader has a big green brain, his subordinates look like the alien from This Island Earth and their "slaves" look like mummies. Somehow, the alien leader is aware of the Time Tunnel and sends a bomb there that he threatens to explode. Naturally, this worries the crew at the Time Tunnel home base, which includes Lee Meriwether and some guy who looks like Donald Pleasence but sounds like Johnny Carson. The time travelers get a British Captain to help them, after they convince him that aliens are real. This is kind of a goofy episode.
Review of Raiders from Outer Space
