Dead Reckoning — Clive Egleton

A victim of brutal mass murder is discovered to have been using the identity of SIS agent Peter Ashton's wife. It quickly becomes clear that someone has breached the top secret SIS personnel files and that an all-too-deadly game is being played out. With every lead ending in a dead end and dead body, time is running out for Peter Ashton and his deadliest adversary is one step ahead.