When the body of a beautiful young socialite is discovered at a party in Westminster Square, the police are quick to rule the death as unsuspicious. But Constable Bryn Summers is not so sure, and with the help of a local barrister, Magnus Walterson, he decides to investigate further. As they question the colourful characters living in and around Westminster Square, including a Hollywood actor, a Ukrainian oligarch, and a famous writer, Magnus and Bryn discover the greed, politics and everyday absurdities of life in one of London's most luxurious postcodes. On the surface, Westminster Square seems an unlikely place for a murder, but as their search for the truth continues, the amateur sleuths get closer and closer to a cold-blooded killer...