If you loved 20,000 Leagues Under the Sea, try Fantastic Voyage
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Richard Fleischer, and they sit in Adventure / Science Fiction territory. If that's the register that drew you to 20,000 Leagues Under the Sea, the second film will land in a comparable space — through a different lens.
What Fantastic Voyage is
Submarines miniaturized and injected into a bleeding patient meet spy thriller. A Pentagon brain smuggled inside a human body drives the mission. The 60s' best techno-fantasy rides on a white-knuckle scale trick.

