The Fetch (Unabridged)- Jack Gerson

It's the 1980s and Alistair Matheson is forging a quietly ambitious path in Government. All is going to plan until a brief encounter with a man who looks exactly like him throws Alistair's ordered world into chaos.
As this doppelgänger crosses his path time and again a series of events are set in motion with increasingly disturbing consequences. Is this double a spy? A conman? Or could he be something infinitely more sinister?