When Agatha Mills is killed in her own apartment in the shadow of the British Museum, there is only one suspect—her husband, Henry. For Inspector Carlyle, it seems like an open-and-shut case. But much to Carlyle's chagrin, Henry refuses to confess. Worse, he comes up with an alternative version of events that is nearly impossible to investigate. Carlyle just wants to put the murder to bed, but when a distraught Henry kills himself on the way to prison, doubts begin to surface. The mounting evidence indicates he may have been telling the truth. In which case, the murderer is still at large . . .