A Dutch boy and girl's idyllic existence is destroyed when they are overrun by a group of Nazi-like mechanical men called "The Screwballs", who lay waste to everything they touch. The Screwballs are later destroyed by a thunderstorm (the rain of which causes them to rust) and the boy and girl's idyllic life resumes.[3]
Tulips Shall Grow essay by Daniel Eagan in America's Film Legacy: The Authoritative Guide to the Landmark Movies in the National Film Registry, A&C Black, 2010 ISBN0826429777, pages 346-347