Being in is everything. Calliope Foster is standing, Pimms in hand, under tasteful bunting at a Richmond garden party. She's here to toast her best friend's engagement.

Being out is murder. Meanwhile, just a stone's throw away, police are pulling a body out of the river Thames. The drowning appears to be a tragic accident - but as Detective Inspector Caius Beauchamp is about to discover, the death is connected to this gathering of who's who in a way that could very well spell scandal.

There may be a wedding to plan, but a dead body will unravel even the best-laid plans.