London discovers what it is like to be Tokyo when sailors capture a large, marine dinosaur and put it on display in a circus, only to learn that the dino is a junior and big momma is coming to raise hell.

Solid British made man-in-suit monster flick features some solid city thrashing, with dino expert Eugène Lourié staging one hell of a rampage sequence through London at the climax. Momma Gorgo could give Godzilla a run for his money with her metropolitin demolition skills.