Dr Morelle Investigates

Locked Room Murder
>The threatening note had predicted the exact time he was to die-9 p.m., later that same day. So as the hour approached, Cartwright had locked himself alone in his study, all doors and windows sealed, with Dr. Morelle and his previously invited house guests in an adjoining room-also locked. Yet when Dr. Morelle re-entered the study after the appointed hour, he found Cartwright's body slumped on his desk, shot neatly through the head-and not by his own hand!

Act of Violence
Dr Morelle is present at the Old Bailey when Robert Griffiths is found guilty of murder and sentenced to death.
Later Dr Morelle is on a working holiday in Wales when he comes across Griffiths very much alive and another murder has been committed. Can Dr Morelle get to the bottom of things before the wrong man is charged with murder?