Even if you have never set foot on Cranley Drive in Ruislip, you will have walked down countless other streets like it. A quiet cul-de-sac of pebbledash semis, it is the epitome of sleepy suburbia and the backdrop for one of the most audacious spy plots of the Cold War.

Inside a bungalow at 45 Cranley Drive was the hub of the Portland Spy Ring: a Soviet plot to steal Britain’s top security naval secrets, including details of the country’s first nuclear submarine, HMS Dreadnought.

When discovered by Britain’s security services in 1961, it revealed a story of unparalleled intrigue which gripped the nation and is the subject of a new exhibition, opened at the Science Museum this week, celebrating a century of British spycraft.

Curators have recreated a version of 45 Cranley Drive - complete with Fifties wallpaper and carpet, as well as the radio transmitter famously discovered hidden under the kitchen floor and is being displayed for the first time.

However Gay Search needs no such reminders to envisage the house. She recalls lying on the carpet to do her homework on occasions when her parents needed a babysitter and unwittingly left her in the care of two KGB secret agents - or as they were back then, the Krogers, a couple purporting to be from Canada; Peter a quiet antiquarian book seller, and Helen his gregarious wife.