A dodgy scientist dies, his work goes missing, and half the people around him are suspected of killing him. It's almost like a locked room mystery, in that all the suspects are gathered together on stage when the lights go out, and when they come back on Sir Claud is dead, and good riddance to him. I'm not always that good at picking whodunnit, but the obvious suspects here were so obvious that I thought it couldn't possibly be them, and I was right. I was entertained to see that Captain Hastings, when he turned up with Poirot, was as dimwitted as ever. "Stay in this room and keep an eye on things," Poirot tells him, basically, and does Hastings do this? He does not. Par for the course, he's distracted by a woman and goes gallivanting off to the garden. I really find it very difficult to see him as anything other than a Labrador in human form: unfailingly friendly and good-tempered, and absolutely distractable.