Chief Inspector Alan Markby of Bamford Police and his girlfriend Meredith Mitchell encountered Meredith's school friend Rachel, who also happened to be Alan's ex-wife, at a prestigious flower show in Chelsea. Rachel's new husband Alex suggested celebrating the meeting with champagne, but he ran into a thorn of some plant, felt unwell and died a few minutes later in his luxury car. The examination established that the spike was poisoned, and this means that Inspector Markby and Meredith are at least the main witnesses to the murder...