 Cocky space ace Tuck Pendelton volunteers to be minaturized and injected into a lab rabbit. Some techno-terrorists foul up these plans and Tuck is mistakenly injected into hypochondriac Jack Putter instead. Now the terrorists are after Jack with all-American hero Tuck shrunk inside him. Their only hope is Tuck s journalist girl- friend Lydia, but Jack has developed a crush on her.