Wayne Szalinski is a brilliant inventor on the verge of completing his shrink ray. But the only thing it seems to be doing, other than blowing up apples, is shrinking the time he spends with his wife, his teenage daughter, and his pre-teen son. Not to mention the stress his constant, and noisy, tinkering creates with his neighbors and their kids. But the problems become much bigger when the kids are accidentally shrunk to ¾ of an inch tall. Now, they must survive the perils of the backyard in order to become full-sized again.