A distant, remote scientific expedition taking place at the North Pole is invaded by a space alien who has reawakened after lying dormant for centuries after a crash landing. A cunning, intelligent alien who can shape-shift, thereby assuming the personality and form of anything and anyone it destroys. Soon, it is among the men of the expedition, killing each in turn and replacing them by assuming their shape, lulling the scientists one by one into inattention (and trust) and eventually, their destruction. The shape-shifting, transformed alien can pass every effort at detection, and the expedition seems doomed until the scientists discover the secret vulnerability of the alien and are able to destroy it.