Pebble Island, a breeding ground for seals is to be sold to a Conservation Group. Mike, Kate and Ben are horrified to find that until the sale is completed, permits have been granted for two professional killers to shoot seals for their skins.

Escaping from China with a microfilm of the formula for the mysterious "Lotus X", Lord Southmere, a Queen's Messenger, is chased by a group of Chinese spies.