When the joker Tommy Tricker plays some practical jokes on some of his friends, his best friend Ralph, a stamp collector, discovers the secret of "stamp travel" to make him travel around the world on a stamp to bring back the mysterious Charles Merriweather, who never returned on a stamp for 75 years.

Pin, a plastic medical dummy, has been the fixation of Leon since youth. Now grown up and orphaned in an accident, Leon brings Pin home to live with him and his sister Ursula, much to her reluctance. Soon, however, Leon's fixation on Pin spirals out of control, and Ursula must face the devastating consequences.