If you want to understand Whetstone, ask Sir Roger Hollis what Palimpsest is.

Just when the National Medical Advisor to the Security Services is on the point of retrieving an injured patient from a hijacked 747 on the tarmac at Heathrow, the authorities pull the plug on a protracted negotiation, with resultant loss of life. Primum non nocere. First do no harm. At the subsequent inquiry, it is the N-MASS, Dr Alastair Cameron-Strange, who is scapegoated, and hung out to dry. Why? Who authorised the storming of Aerolineas Argentinas Flight 301?

First minded to quit medicine and get out, sheer bloody-mindedness drives Cameron-Strange to open a file on a high ranking government minister, the Enterprise Czar, erstwhile Managing Director of The Conglomerate, Sir Roger Hollis. His researches take him from London to Edinburgh, thence to the north-west tip of Scotland, where, accompanied by the mysteriously intangible Kathryn Hathaway, he discovers The Conglomeratess dreadful secret, Palimpsest, and solves the riddle of AA Flight 301.

But theres no way back to London from Cape Wrath. Is there?