Cushing is a scientist brought to an Irish island to study some newly discovered boneless corpses. The bodies turn out to be those of a doctor and his assistants who have been working on a cancer cure. What they have developed instead is a bizarre silicon-based life form which feeds on calcium. The creatures, which multiply every six hours, kill practically everyone on the island. Once a dangerous isotope is injected into the island's cattle, however, the creatures die. A rather shaky plot is boosted by Cushing's ever effective performance and Fisher's tight direction. Fisher also helmed a number of Hammer horror films, including THE CURSE OF FRANKENSTEIN and HORROR OF DRACULA.