A team of Danish mining engineers discover the tail of a huge prehistoric monster buried in the ice near the arctic circle. The Professor Martens and the Doctor Dalby assume that it concerns a gigantic reptile. A piece of its tail recuperated under the ice allows to imagine that the thing measured near 35 meters.
The tail is taken to Copenhagen where it is preserved in a refrigerated room. Studies led by Martens and Dalby allow to assert that the monster is able to regenerate itself. Remain the the reptiles are then confined in an immense ferments, immerse in a nutrient liquid so as to demonstrate their incredible discovery. But the growth of the monster challenges all waits and by a stormy night, the beast nicknamed "Reptilicus" escapes the laboratory by killing the Doctor Dalby.
Traces of the beast demonstrate that the former has found refuge in the sea but a short while after its escape from the laboratory, a coastal village is attacked. A military detachment led by the General Mark Grayson is sent to its encounter.
But the huge monster resists to the attacks led by the soldiers, protected by a thick series of ultra protective scales.
Impossible to stop, the monster spreads terror in surroundings villages. The General Grayson succed in repelling the beast out of quarters of the city. The task is not easy, all the more that Reptilicus spits on soldiers a mortal acidic substance. The Professor Martens warns Grayson on the manner to kill the monster. By using a too much concentration of explosives, the monster could spread in several pieces each capable to regenerate and to produce a new reptile...
Spoiler ! the end of the story is revealed below…
It is then decided to poison the beast. Some liters of one of the most harmful poison are installed in a missile that will reach its target. The battle against the monster is won but on the bottom of the ocean, a small piece of "Reptilicus" begins its regeneration process.