It is a matter of cinematic certainty that James Bond will wander, largely untroubled, into the heart of his nemesis’ heavily defended lair. Once there, he tends to dispatch with the occupants before blowing up the place and escaping by some unnecessarily complicated route.

In the real world the battle between homeowners and their would-be assailants is a far more evenly pitched affair. On the streets of London, where trade in multi-million pound homes is booming, it is also becoming big business under the simple equation that if the criminals are getting more sophisticated, so too must the measures to defend against them. Bulky security cameras and dinner-bell style alarms are being replaced by delicately-tuned networks of gadgetry.

“The days when having a foolproof security set-up was something only politicians or pop stars did are over,” says Adam Ashmead-Bartlett, a UK-based security consultant with Isis Risk. He and his team of ex-special forces men have years of experience in helping large corporations to tackle the kidnap and extortion of their workers. Today, they dedicate an increasing amount of time to designing and implementing security systems for London’s wealthiest homeowners.