When an earthquake strikes the island of Canna, rocks are split open and the island begins to crumble. But no one could have foreseen that an even more deadly threat was to be released from the fracturing ground - swarms of poisonous spiders.
With the islanders running for their lives, Department Z is called in to help save them from the freak disaster.
It is soon discovered that the release of the deadly insects is not so coincidental when a vicious criminal maniac is uncovered. But how can Department Z, Britain's secret service elite, stop the eight-legged infestation?