In Univille, Artie is barking at Claudia for attempting to upgrade her new Farnsworth, and Pete's stuff still hasn't arrived at the post office and the locals hate him. The postmaster barks at him that the branch has been shut down. As Pete and Myka pass a veterinary office, Pete catches the vet's eye, but she's soon distracted by a flash of blue light and three Marines walking by. Moments later, Artie calls an emergency meeting with Pete, Myka and Claudia to let them know that there's an artifact in Univille, gives them their cover - IRS agents - and tells them to start interviewing locals.
At Leena's call for help, Mrs. Frederic arrives at the B&B, with company: Mr. Valda, a Regent, and the mysterious Taka. Taka will remove the residue MacPherson left in Leena's mind when he was controlling her, using MacPherson's own means: the Pearl of Wisdom. Mrs. Frederic balks - the risks are too great - but Valda insists, and they proceed.
Pete and Myka interview the veterinarian, Kelly, who tells them about the patch on the chest of the Marines: a fire-breathing wolf. Claudia tries her luck getting the parts to repair the Farnsworth, but finds instead a cute hardware store employee named Todd who is quick to guard his boss's apartment at the back of the store. Suddenly Claudia's Farnsworth goes haywire, and as she ducks outside, a mounted cowboy races past, but the image shimmers into nothing. And blocks away, Pete and Myka get caught in an old-fashioned Western showdown.
Searching for the source, they investigate a huge power drain at the hardware store, their Farnsworths going haywire upon arrival. Moments later, the mirage of a gladiator and tiger appear. Pete recognizes the mirage gladiator just as he lunges at Pete and inflicts a very real wound, and they realize that if they don't stop the mirages, they could hurt the town. Claudia rigs the Farnsworths to find the source, and they discover the next mirage happening at Kelly the vet's. Pete realizes that all of the mirages are from movies starring the same actor, Raymond St. James, and the next one, Dr. Doomsday, could blow up the whole town of Univille.
Artie has discovered a discrepancy in the warehouse: Philo Farnsworth invented a three-dimensional camera and projector, designed to make wartime opponents believe the US had much more artillery than was true. The warehouse has the camera - but not the projector. The team goes on the hunt, and finds that the postmaster has been watching a Raymond St. James marathon using what she thought was just a cool projector. They sever the connection, but this is not enough to stop the mirages - they must record something new and use it to override the marathon.
The team converges on the site of the Dr. Doomsday mirage and, using Claudia's technical wizardry, Myka's photographic memory, and spare Farnsworth parts, rig the camera to record an emergency broadcast, and obliterate Dr. Doomsday.
Mrs. Frederic and the visitors have wrapped up their work with Leena. Taka was unsuccessful, so Mrs. Frederic steps in and called forth the voice of MacPherson. Mrs. Frederic's task completed, Leena asks if she will be alright. Mrs. Frederic gives her an uneasy, "Yes."