Weird Science - Season 4 Episode 25 Swallow 13

Chett swallows a very rare invitation (complete with directions) to an underground rave. So, Lisa miniaturizes herself, Gary, Wyatt, and a space ship. They take a ride inside of Chett in hopes of getting the directions back. Just as in ""Fantastic Voyage,"" Lisa, Wyatt, and Gary get to see way too much of Chett... The complete inside of him. However, during the trip, Chett's girlfriend Sharon breaks up with him, and Wyatt gets Post Miniaturization Stress-Syndrome, causing him to go mad. Wyatt tries to ruin the plans of the mission, and the ship ends up running out of oxygen. Lisa and Gary need stone cold Chett to cry, or else be trapped inside his body with no air.