Firstly, about the geocache: it is in a magnetic 35 mm film canister. Please be discrete and respectful as this is a residential area. And you will need to bring your own pen/ pencil! The geocache is accessible by wheelchair, but someone in a wheelchair would need an aid/ picker /reacher to grab the cache.
Now settle down and get comfortable for the disturbing true story of the Portland Spy Ring that operated out of none other than leafy, suburban, 'innocent' Ruislip, from a bungalow on Cranley Drive, right next to this very geocache!
Lona Cohen (1913-1992) and Morris Cohen (1910-1995) were a married American couple who had become undercover Soviet spies because of their Communist beliefs. After narrowly escaping arrest by the American intelligence services in 1950 they fled the USA, never to return.
However, in 1954 they resurfaced in the UK. They moved into a bungalow at 45 Cranley Drive, Ruislip under the new names Helen and Peter Kroger, where they set up a business selling antique books, which served as their cover for spying operations.
A tip-off from a triple agent in 1959 roused the suspicions of MI5 (the United Kingdom's domestic counter-intelligence and security agency), and Helen, Peter, and three of their colleagues in espionage [these 5 people together were known as the Portland Spy Ring] were all put under surveillance. On January 7th, 1961 all 5 were arrested. The Krogers were arrested at their home in Cranley Drive and were caught red handed trying to destroy evidence. After a full search, the bungalow was found to be full of espionage equipment, confidential photographic material, and large sums of money.
At trial, Morris/ Peter was sentenced to 25 years in prison, while Lona/ Helen got 20 years. However, in a further twist to the tale, in 1970, both were swapped for a British spy, named Gerald Brooke, who was in Soviet custody. After this, Lona and Morris relocated to Russia, where they saw out their days training Soviet spies. It is not known whether in this time they missed Ruislip or not. They both passed away in the mid 1990s.
A few years after their passing, Lona and Morris Cohen were two of the Soviet spies that featured in a set of stamps commemorating former Russian spies. The stamps were issued by Russia in 1998:
More information: Wikipedia - the Portland Spy Ring
BBC news article - The spies in a suburban bungalow