介绍：When a series of apparently minor thefts plagues a university hostelry run by Miss Lemon's sister, Poirot is recruited to investigate. Celia Austin, a pharmacological major, confesses that she is a kleptomaniac and responsible for most of the thefts but denies stealing several objects including a stethoscope, light bulbs, and a student rucksack. Furthermore, she claims to know the other thief and vows to help return the missing items. Unfortunately someone substitutes an overdose of morphine for one of her sleeping powders, and she takes the identity of the thief to the grave. Japp connects the murderer's m.o. with a cold case he had investigated ten years earlier, but the prime suspect in that crime, a powerful statesman, now lies dying in a local hospital. Despite numerous obstacles, Poirot is able to link the killing to an international diamond smuggling ring but not before the murderer claims more victims.

介绍：第七季共2集　　1、The Murder of Roger Ackroyd 罗杰疑案（罗杰·艾克罗伊德谋杀案）　　2、Lord Edgware Dies 人性记录

介绍：《大侦探波洛》第六季共4集，均改编自长篇小说，片长约100分钟，自本季往后所有故事均为长篇　　1、Hercule Poirot's Christmas 滴血的钻石　　2、Hickory Dickory Dock 国际学舍谋杀案　　3、Murder on the Links 高尔夫球场的疑云　　4、Dumb Witness 无言的证人