A missing plane resurfaces - and so do long-submerged secrets...

An RAF Dakota, presumed lost at sea during World War Two, has just been discovered at the bottom of a drained lake over twenty years later - complete with the skeletal remains of the pilot and a strange cargo of rubble. Why are the Soviets so interested in it, even attending the dead man's funeral? Why has unassuming civil servant David Audley been tasked with leading the investigation - and what was the plane carrying that some will kill for?