在这部四大魔头剧情/犯罪/悬疑片中,本集根据阿加莎·克里斯蒂的同名小说改编，由于原著本身情节较为混乱，属于波洛探案系列中的一部风格特异的作品，因此编剧马克·加蒂斯在影视化的时候做了较大的改动与调整。故事讲述了二战前夕，在和平党人罗兰举办的象棋联欢会上，俄国象棋大师暴毙而亡，波洛发现棋桌上有导电板，表明大师应是触电致死。与此同时，记者泰梭不断收到匿名信件，声称将有四魔头出现，导致英国陷入混乱。这些看似无关的事件背后究竟存在着怎样的联系呢？
A Russian grand master dies mysteriously during an international chess match. The case is related to a political intrigue involving the so-called Peace Party and its leaders Madame Olivier and Abe Ryland. Poirot investigates with his old friends Hastings, Japp and lemon, helped by a reporter and a minor actress, but the quartet must soon fight a dangerous battle with the Big Four, a secret society manipulating for their own personal chess game a great number of international celebrities.
