The Adventure of Johnnie Waverly - S1-E3
Plot hole: Forgiving the implausibility that nobody checks their own watch at the time of the kidnapping, the clock in the living room strikes 12 supposedly ten minutes early: everyone blindly storms from the room when the chimes have not yet ended, and reaches the supposed perpetrator who is by the side entrance. They talk to him briefly and the clocktower signals now the real noon. It's hard to see how 10 full minutes could have passed, and even harder when everybody runs back to the house, to find the clock there signaling 12:11: it took them a mere minute to get there, what took them so long the first time? (00:30:00 - 00:31:30)
The Adventure of Johnnie Waverly - S1-E3
Plot hole: When he is taken away from the mansion, Johnnie is hammering with his fists on the car windows, as if he was genuinely in distress and resisting the kidnapping. But as we know, that's not what is happening, he knows his captor well and came willingly. (00:31:25)
The Adventure of Johnnie Waverly - S1-E3
Plot hole: In the original story, it is made clear that Mrs. Waverly is the one in the family with the wealth, but it does not go as far as having everyone, guests included, eat plain rice and boiled potatoes, and have the mansion dilapidated with restoration work left unfinished for years. This creates several plot holes: nobody would be interested in asking lavish amounts of ransom money to people who live an impoverished life, and most importantly, the husband would never be able to justify being able to have enough money to suddenly resume construction work on the house (in the original, he simply wanted to use it as spending money).
Four and Twenty Blackbirds - S1-E4
Plot hole: In the denouement, Poirot says explicitly that the culprit sent the letter to the victim - but the letter in question, in this dramatization was stated earlier (in a change from Agatha Christie's original) to be an invitation to the art gallery, and the culprit is not the manager/art gallery owner! In the actual short story the letter was a personal message of entirely different nature, written and authored by the culprit.
Plot hole: In the original novel, the victim's voice is described as "shrill." In here, it's quite the opposite. When the trick for the alibi is performed, the relevant lines are not read by John Normington, thus Poirot's exposition at the end, with the girl providing the voiceover, indirectly further exposes its unbelievability.
Plot hole: Hastings came over to assist Poirot in his case, posting guard overnight. He offers to drive Poirot back to the villa since Poirot is in a rush and has figured out of the culprit. Poirot approaches the villa just in time to come across Mrs. Vanderlyn on her way out. Poirot rushes to Hastings then to give chase to the woman but...Hastings has pulled out all the plugs and is cleaning the carburettor, just doing some random maintenance to the car that would take him, in his words "an hour" to bring back to work. On a one-day job, Hastings crippled their own car for no reason whatsoever. This is beyond stupidity.
Plot hole: Nobody hears the sound of a gun being fired past a door they were waiting almost in front of, and the police cannot tell apart a shot fired point blank by one fired 20 feet away and probably at a very sharp angle. Moreover, the bleeding should be all over his face, since leaning the way it is shown in this adaptation is most likely to lead the victim to fall over, and even leave bloodstains out of the window and on the ground below, which someone would have noticed in the crowded factory.
Plot hole: The whole premise of the plot is that nobody is staying at End House but Nick (and the servants); she even says explicitly that there is just one room that is usable and everyone else stays at the Majestic. During the party though, Freddie tells Maggie to go get her coat which is "in my room." They are at End House, not the hotel, how would Maggie have a room there? (00:35:00)
Plot hole: The hole in the hat was pre-existing and the bullet was fired in advance and dropped. Poirot notices immediately the hole when Nick puts the hat down but somehow missed it while she was wearing it as she supported him. He also does not notice that the bullet has not been fired at that time - which would have been still hot if just fired, not at all if dropped. Most importantly, in the spot where they were sitting, it's not even possible to think where a shooter could have ever been hidden; nobody wonders where the mysterious shooter could have been or cares to investigate the circumstance despite knowing the very moment the supposed shot happened. The fact is basically ignored throughout the rest of the episode.
Plot hole: The killer's plan needs to have Maggie at End House - but it's achieved through Poirot's proposal to have Nick call her to act as added protection. But this makes no sense; Maggie's presence would have not protected Nick in any of the alleged attempts to her life; the frame would have crushed her too, she would have died in the car, she couldn't have prevented the rock from falling, and Nick was shot while the most famous detective was with her, even! A random little girl from Yorkshire would have not mattered, so it makes no sense that Poirot endangered someone for no gain.
Plot hole: When Poirot and Hastings break into the house, they search the entire house for the box, without success. However, later on, when they are in the kitchen, the housekeeper comes down the stairs - having been lying in wait for them. How did Poirot not run into her when he was initially searching upstairs, particularly when he was making such a thorough search?
The Disappearance of Mr. Davenheim - S2-E5
Plot hole: The safe is behind a painting that acts like a real door. When Mrs Davenheim spots it, it's wide open. But Japp questioned her in the same room and the painting was in place back then. It really makes no sense that with a story depicted as being so big (it makes the first page of the national newspapers) and with an investigation in place, nobody in a week has checked the safe at all. (00:27:50)
The Disappearance of Mr. Davenheim - S2-E5
Plot hole: The killer has a perfect (in movie logic at least) plan but he amplifies its risks to 1000000% getting caught on purpose with an incriminating item that links him to his secret identity and that is amazingly likely to have him questioned and face the wife of the deceased (who recognizes him in 0.5 seconds) and other witnesses. Even without Poirot it is impossible to imagine a trial happening without him having to appear in some capacity. And in this TV dramatization, the motive of Lowen to hate Davenheim is obvious, but not the other way around, so it appears even more baffling that he'd utterly ruin his perfect escape just to mess with a rival apparently he had a upper hand on. Moreover, the dramatization makes his plan even more absurd, as instead of pawning the valuable ring like in the original and being only marginally involved, here he has it days after the murder, and robs the Inspector chief! Any bobby would do. Finally, here he also wears prosthetics, again drawing attention.
The Adventure of the Cheap Flat - S2-E7
Plot hole: The professional hitman from the US does not have a gun of his own, and does not bother in the long time elapsed between the apartment's hit and the nightclub (it could even be hours) to check if the gun he just grabbed is loaded or not. Who in the world would not take a split second of his time to peek at the cylinder and see how many bullets does he have? An assassin planning to kill with that gun, even.
The Mysterious Affair at Styles - S3-E1
Plot hole: To enter Mrs. Inglethorp's bedroom, Hastings and John have to ram the door and certainly break the lock (it is replaced, so there was damage done). The doctor leaves the house very early in the morning just after ascertaining the death of the woman, and tells them he "locked both rooms" (the room has three doors but one is bolted internally, allegedly). But the door was broken, and in fact when Poirot arrives, which is early in the morning, as Hastings went to the village waking him up, he finds a brand new lock in the door. They would have needed to summon a locksmith at maybe 6 or 7 am, to repair an internal door in a country house, and he should have done it on the spot (also, the door frame itself is more likely to suffer damage than the lock itself, no real damage was shown during the scene). The keys are also all in the same bunch and not looking in any way different (one should be brand new and shiny). (00:28:45 - 00:37:40)
The Mysterious Affair at Styles - S3-E1
Plot hole: Can't fault this massive plot hole to the adaptation, but to the source material; the culprit (forgetting the stupidity of writing an incriminating letter detailing the plan to murder someone, and put it in a desk he shares with her) since there are people outside the room that are about to enter, tears the letter in 3 neat vertical strips, rolls them, puts them in the vase on the mantlepiece, and then opens the side door to slip away...instead of simply pocketing the letter and going through that same door. Nobody was going to search him or anything and could have burned it, torn it into confetti, anything, later. It takes way way longer to do what he did, which needed him to stay there in the room increasing the chances of being found out. And of course he and his accomplice do not retrieve the letter after.
Wasps' Nest - S3-E5
Plot hole: There are some additions to the original short story in this dramatization, but they create a little problem since Hastings does not come with Poirot for the finale, and in fact is told to stay home in a rather demeaning way. Without Hastings, it's hard to imagine Poirot could break into Langdon's house, since Capaldi when is not playing creepy clown is a sculptor working at home; Poirot would need an accomplice to create a diversion. And, even sillier, Poirot tells Hastings to go buy him some washing soda, but he needs the soda to pull off the switch. Hastings should have joined him at least to give him the soda once Poirot has visited the doctor.
The Tragedy at Marsdon Manor - S3-E6
Plot hole: The murderer is in possession of chloroform from the doctor's cabinet, but there's no realistic timeframe when they could have done it, nor any explanation why the doctor notices it completely at random when Poirot visits, just approaching the medicine cabinet, something he routinely opens and looks through during the day.
The Tragedy at Marsdon Manor - S3-E6
Plot hole: The murderer planned everything making it seems accidental. They perfectly managed to fool the coroner and need only to be alone at the mansion to get rid of the murder weapon. So what they do is...they go through great risks to make everyone know someone tried to murder the wife too, making it obvious that there is a killer at large, which only makes the investigation more stringent and most importantly, keeps the police on the premises for surveillance preventing them from disposing of the weapon (like almost everything in this episode's plot it is not a flaw of the original story, but of the dramatization, who added practically every minor character).
The Tragedy at Marsdon Manor - S3-E6
Plot hole: It is revealed towards the end of the episode that the painting Mrs. Maltravers did when the murder took place was not painted that day and that time of the day, because it had the wrong shadows. But we actually saw what was on the canvas when the secretary was leaving to go to the bank, and it was that exact painting in an early state. She also came up with the idea for the murder the night before, making even more unbelievable that she'd just have the alibi painting ready and waiting the morning after. That without mentioning the fact that the murder itself as described is not something that would have required an amount of time needed to make a whole painting, and that she could have finished it later anyway (she gave it to Hastings a day later, after all).
Answer: He definitely says "Belgian", but the subtitles get it wrong and show him saying "American."
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