A scientist is injured in an assassination attempt, so a group of scientists and their experimental submarine are miniaturised and injected into his blood stream. The plot is about minaturisation that also starts to become part disaster film once they are moving around the body. There are excellent effects for the period and these make the film watchable.
Donald Pleasence
Raquel Welch
Stephen Boyd 
Arthur O'Connell
James Brolin 
3/5