And Hope to Die — Roger Ormerod

Philipa Lowe is asked to attend an auction sale to judge the authenticity of a watercolor painting by her late husband, Graham Tonkin. Being no art expert, she is concerned that her journey will be unproductive. But, where is the elusive birthmark? Only she can testify to this nebulous proof, and even she is baffled when it is not there -- and then it is. But the trip is not a waste of time, as it reveals a suicide that may have been a murder, and it is only the ubiquitous birthmark that can reveal the truth of the sealed room, which clearly could not have been sealed if there had been murder committed inside. This at least provides interest for Philipa, but she probes perhaps a little too closely into the appalling facts that lie behind this sudden death, and in doing so she very nearly meets her own.