In order to save an assassinated scientist, a submarine and its crew are shrunk to microscopic size and injected into his bloodstream.

Four explorers are summoned to Peru by the brilliant physicist Dr Thorkel. They discover a rich source of radium and a half-mad Thorkel who shrinks them down to one-fifth their normal size when they threaten to stop his unorthodox experimentation.

The scientist father of a teenage girl and boy accidentally shrinks his and two other neighborhood teens to the size of insects. Now the teens must fight diminutive dangers as the father searches for them.

Fed up with being targeted by the neighborhood bully, 10-year-old Lucas Nickle vents his frustrations on the anthill in his front yard ... until the insects shrink him to the size of a bug with a magic elixir. Convicted of "crimes against the colony," Lucas can only regain his freedom by living with the ants and learning their ways.

The joke's on absent-minded scientist Wayne Szalinski when his troublesome invention shrinks him, his brother and their wives so effectively that their children think they've completely disappeared. Of course, this gives the kids free rein to do anything they want, unaware that their parents are watching every move.