Special Agent Kala Golightly has been assigned the mission of recovering a devastating weapon that has been accidentally sent back through time. Traced to Wiltshire, 1934, the timer on this weapon is running and if Kala doesn't recover it before it activates, it will become capable of genetically re-engineering everything that comes into contact with it. In this event, Kala is under orders to detonate a nuclear device that will destroy the entire area.

Charles Rigby, resident of the small village of Marpling, discovers the device in his back garden. It is accidentally triggered and takes over some wasps whose nest was nearby. They are transformed into carriers of psionic intelligence.