In her most dangerous case yet, Harriet Martens finds herself the victim of a cunning poisoner.

Whilst relaxing with her husband at the Majestic pool one hot August Bank Holiday, Harriet does not expect the refreshing glass of Campari soda at her side to conceal a deadly drug. When she awakes from a doze she is no longer by the water, but in a hospital bed recovering from a near fatal dose of Aconitine.

As Harriet makes her slow recovery, she tries to come to terms with the terrible fact that someone wanted to kill her. Even more difficult for her to face is the knowledge that she must find the person responsible, if anything for her own peace of mind. But no sooner has she mustered enough energy to begin making tentative enquiries and initial investigations, than the poisoner strikes again. And this time he is successful . . .