Hickory Dickory Dock (sometimes printed as Hickory Dickory Death) is a 1955 mystery novel by Agatha Christie.
Hercule Poirot notices that his secretary Miss Lemon, usually machine-like in her precision, made three, count 'em, three mistakes in the letter she typed for him.
When he asks Miss Lemon about this she explains that she's worried about her sister, Mrs. Hubbard, who supervises a student hostel in London. It seems that one of the residents in the hostel has been stealing various items, including a stethoscope, a backpack that was found cut to pieces, a cookbook, lightbulbs, a diamond ring later found in a bowl of soup, a makeup compact, and others.
Intrigued, Poirot pays the hostel a visit. One of the students, Celia Austin, confesses to the theft of most of the objects, but denies a few, like the rucksack and the diamond ring. Still, it seems that the matter has been resolved—until Celia is found dead after someone slipped morphine into her coffee. Poirot winds up investigating a remorseless killer.
- The Alcoholic: Mrs. Nicoletis is irrational and prone to mood swings. The reason why is revealed when the cops force open her cabinet and a bunch of empty liquor bottles spill out.
- Bad to the Last Drop: When some of the characters suggest a coffee break, Nigel says "If you can call this fluid they serve—coffee."
- Brits Love Tea: Poirot is served tea at 5 pm, but he doesn't like the English ritual of tea, so he gives his to Inspector Sharpe.
- Continuity Nod: When Poirot arrives at the hostel in Chapter 4, one of the students mentions that he got a man off the hook for the murder of a charwoman, which was the plot of Mrs. McGinty's Dead. In that same chapter Poirot tells a story of subtly suggesting to a client that it would not be a good idea for the client to murder his wife—that's short story "The Nemean Lion" from The Labours of Hercules. Later he makes a random reference to Countess Vera Rossakoff, a character from "The Capture of Cerberus", another story from The Labours of Hercules.
- Dead Man Writing: Sir Arthur Stanley's will contains a letter to his lawyer Endicott in which he recounts how Nigel murdered his mother, and how Sir Arthur made Nigel write a confession that would serve as Sir Arthur's "in the event of my death" letter.
- Enfant Terrible: Nigel Chapman is referred to as a grown-up version of this.
- Framing the Guilty Party: Nigel Chapman does what is called "double-bluffing".
- He Knows Too Much: Poirot actually says "She knew too much" when explaining Celia's murder—Celia had found out that Nigel had changed his name and she also found out that Valerie had left the country with a false passport.
- Incriminating Indifference: Subverted. Nigel Chapman, after Patricia is found dead, is incredibly upset, and because of this, the police say that he can't be the killer. Poirot points out that his tears were indeed genuine, and probably more so because he loved her and had to kill her.
- Never One Murder: A frequent Christie trope. Mrs. Nicoletis, who owns the student hostel, is poisoned a little more than halfway through, and poor Patricia is bashed over the head and killed near the end.
- Never Suicide: Celia's death is made to look like she killed herself with morphine, but Poirot and the cops quickly figure out that she didn't, by noting that the pen she supposedly wrote the suicide note with had the wrong color ink, and the note itself was actually ripped from another letter in which the message had a different context.
- O.O.C. Is Serious Business: Poirot is flabbergasted when Miss Lemon makes three mistakes in a letter, as she's worried about her sister, which sets Poirot on the trail.
- Phoney Call: Nigel appears to have an ironclad alibi for Patricia's murder when Pat calls into the police station when he's being interviewed. Nigel and the cops go back to the hostel together to find out that Patricia has been freshly murdered. It turns out that Nigel's partner Valerie placed the phone call pretending to be Patricia, and Nigel had actually killed Patricia before he went to the police station.
- Separated by a Common Language: Mrs. Hubbard says Sally Finch the American student was "going out to a party in what she calls 'formal dress'—evening dress to us."
- The Sociopath: In a letter to his lawyer, Nigel's late father describes his son as "one of those dangerous misfits who have neither conscience nor pity."
- Sticky Fingers: Played with, when it seems there's one of these at large in a student boarding house. Not only was Celia actually faking to get the attention of a psychiatry student she's in love with, but she was actually given the idea by a fellow lodger... who turns out to be the accomplice of a third resident who is a smuggler and used Celia's faked condition to disguise the creeping around he had to do in the course of his activities.
- Tempting Fate: Chapter 6 ends with Mrs. Hubbard thinking "It's all over now" after Celia has confessed to most of the petty thievery. The next chapter has Celia turn up dead.
- Title Drop: Nigel starts twisting around the words to "Hickory Dickory Dock", apparently inspired by the fact that the hostel is located on Hickory Road. Poirot also says the nursery rhyme on the last page.
- Unable to Support a Wife: Colin explains that even though he'd asked Celia to marry him, they were going to wait quite a long time, as Colin the psychology student wasn't yet earning enough to support her.
- Uncle Tomfoolery: There's a lot of racist humor involving Akimbobo the African student. In Chapter 9 he asks for samples of Celia's hair and fingernails so he can solve the murder with some sort of witch doctor ritual.
- Victoria's Secret Compartment: Where Mrs. Nicoletis drops the key to her cabinet in an effort to stop the police from opening it. They ignore her and force it open.
- Year X: A pretty weird example since there was no need to not be precise. But Nigel's confession to the murder of his mother dates the crime to "November 18, 195—."