In a small English village, Dr. Laird and his assistants Gil Graham and Michele Dupont are conducting experiments with magnetic fields. The results may have military applications as his equipment can rearrange molecules to make solid metal brittle or stiff metal pliable. Gil notices that the magnetic and affecting the village but Laird won't stop his tests. A mysterious stranger, known simply as Mr. Smith, assists them in solving several mysteries, including a series of attacks in a public park. Their greatest challenge is the sudden appearance of giant insects, bugs that have mutated as a result of the experiments.