The devious Saurians have found a way of flawlessly impersonating humans so as to infiltrate the Searcher and fly it into an enemy’s defense shield, destroying everyone aboard. The good news: Buck, being from the 20th century, can see through the disguise and views them for the slimy, reptilian creatures that they are. The bad news: he’s sick with a rare virus, so everyone thinks he’s just hallucinating. The Saurians are on to him, so they steal a sample of his blood and “realign” their image devices, but Buck by now takes matters into his own hands by decreasing the ship’s temperature, paralyzing the cold-blooded intruders and sending them to the brig, all before certain disaster were the Searcher to continue its programmed course.
Excellent episode is nail-biting from start to finish. Borrowing more than a bit from the “Nightmare at 20,000 Feet” episode of The Twilight Zone, it employs the old “who’s really crazy?” trope to fine dramatic effect. Good makeup of the Saurians makes them intriguing enemies – if the show were to continue on, they could have been good continued foes, like the Klingons on Star Trek.