Ocean Pioneer I, an automated tanker carrying liquid alsterene, sails into a mysterious sea mist and explodes. Six months later, Lady Penelope launches Ocean Pioneer II, having thoroughly searched the ship beforehand for signs of sabotage. Meanwhile, International Rescue respond to a distress call from Oahu in the Pacific which has been hit by a typhoon, but suddenly all radio transmissions are blacked out leaving the organisation blind and deaf. Brains traces the cause of the interference to a reaction between OD60, a sea fungus used in the production of dog food, and liquid alsterene fuel in close proximity: bringing them even closer together results in a huge explosion. Jeff realises that this reaction must be the cause of the destruction of Ocean Pioneer I. Then Lady Penelope learns that there are large deposits of active OD60 in the Mediterranean and Ocean Pioneer II is heading straight for the area loaded with liquid alsterene!