The next day, Luke reads about Miss Pinkerton's death, then about the death of Dr. John Humbleby a few days later. Dr. Humbleby was the one the affable old lady thought would die next. While the cause of his death seems to be thanks to an infection, Luke decides to look into the matter himself.
Pretending to be a researcher into superstitions and witchcraft, Luke begins his investigation into the multiple deaths. What all the deaths have in common is that the victims were largely seen as pests and none of them seemed to have died by foul play. With the help of Bridget Conway, a secretary of Lord Whitfield (in some editions he's called Easterfield) who's much smarter than she looks, Luke might be able to figure out who the murderer is and stop the killings for good.
Murder is Easy (published as Easy to Kill in the US) is a 1939 mystery novel by Agatha Christie, and the fourth installment in her Superintendent Battle series.
The novel has had multiple live-action adaptations, from television movies to stage plays. In 2009 when the Marple TV series reworked it so Miss Marple could solve the case alongside Luke.
The BBC produced a miniseries adaptation in 2023.
This novel contains examples of:
- A God Am I: Lord Whitfield eventually realizes that all the victims had wronged him in some way, and declares that God himself must be punishing anyone who dares to cross him. Luke is naturally unnerved by this and begins to suspecting him of simply killing them himself. This turns out to be the result the real murderer was hoping for.
- Asshole Victim: In-Universe, it is mentioned how nobody really misses Harry Carter or Tommy Pearce.
- Bad People Abuse Animals:
- The story Honoria Waynflete tells where Lord Whitfield killed her pet bird for petty reasons. In reality, it was Honoria herself who killed it, and this is the real reason for their broken engagement.
- Tommy is said to have killed small animals for fun, which is one of the reasons no one is really sorry he's dead.
- The murderer killed Doctor Humbleby by deliberately wounding a cat and letting the wound fester, jabbing the doctor with scissors, and then insisting on dressing the wound with bandages they’d injected with the pus.
- The Bartender: Harry Carter, the first victim. He also drank some of his own stock and wasn't easy for his wife and daughter to live with.
- Beta Couple: Dr. Thomas and Rose Humbleby have a stable, largely off-screen relationship compared to the leads.
- Betty and Veronica: Downplayed, as Luke is attracted to Rose Humbleby, who is a sweet girl and inspires protective feelings in him, and Sugar-and-Ice Personality Bridget Conway, whom he repeatedly compares to a witch. However, he falls in love with Bridget and never goes beyond admiration and protectiveness towards Rose (especially since while Bridget's engaged to a Meal Ticket, Rose and her fiance are a love match).
- Boyfriend-Blocking Dad: Murder victim Dr. Humbleby quarreled with his younger partner Dr. Thomas over Thomas's relationship with Humbleby's daughter.
- Car Fu: The old woman was hit by a car on her way to report the Serial Killer. Given that the murderer makes the murders look like accidents, it seems likely that the murderer drove that car. Subverted, as it turns out the murderer actually pushed her into the street in front of the car.
- Disposable Fiancé: Lord Whitfield to Bridget, who, however, admits she was fond of him.
- Everyone Is a Suspect: Well, not everybody, but part of the trouble facing Luke is that he can find a number of different people in the town who would have plausible motives to kill at least one of the victims.
- Evil Genius: Fitzwilliam and Battle both comment on Waynflete's unusual intelligence in committing a series of murders and remaining entirely above suspicion, while pointing the blame at somebody else.
- Face of an Angel, Mind of a Demon: Or rather voice of an angel for Tommy Pierce, the school bully and one of the victims.
- Jerk with a Heart of Gold: It's very hidden, but Lord Whitfield has one.
- Little Old Lady Investigates: Luke asks Honoria Waynflete for help as she seems like a sharp old woman. Subverted in that she's the murderer.
- Make It Look Like an Accident: The murders were initially done in ways that looked like illnesses, falls, ingesting the wrong medicine, and the like.
- Medication Tampering: Amy Gibbs died by drinking hat paint instead of her cough medication.
- Motive Rant: The killer delivers a lengthy confession to Bridget as they're about to kill her, explaining their motives and how they committed all the murders. Judging by their enthusiasm, they've probably been waiting for this moment for a very long time. This also gives Luke enough time to save her.
- Pitbull Dates Puppy: Major Horton and his wife had a relationship like that. The Major himself is interestingly a breeder of dogs, but seems to very much be the submissive member of the couple and seems to genuinely miss his late wife when describing things she did that Luke think would have driven some spouses to murder.
- Running Over the Plot: A variant. An old lady shares her fear of a murderer with a young man on the train. A few days later, the guy learns of her death in an automobile accident and investigates. It turns out that while the driver himself had nothing to do with the story, the murderess pushed the old lady in the way and gave the wrong licence number to frame another character.
- Self-Made Man: Lord Whitfield was born the son of a local boot merchant, and now is quite wealthy, having founded a chain of newspapers. Honoria Waynflete hates him for this, as her family used to be wealthy and now Whitfield owns her family's house.
- Serial Killer: The novel has one of the higher body counts in Agatha Christie's novels. Five people are dead before the story even begins, followed by two more murders and an attempted third. While the motive turns out to be a convoluted revenge plot, Honoria also makes it clear that she enjoyed every second of killing all those people.
- Small Role, Big Impact: Mrs. Humbleby has very little dialogue or pagetime but has been suspicious of the correct person for some time and reveals these suspicions at an ideal time to prevent the final murder.
- Slap-Slap-Kiss: Luke goes from essentially calling Bridget a Gold Digger to exclaiming his love for her, and she hits him right back with accusations of jealousy. They eventually get over that blow-up.
- Slipping a Mickey: The killer tries to drug Bridget in order to murder her, but she sees through it. Instead she plays along and pretends to drink, hoping that the killer will keep their guard down.
- Turned Off By The Jerkass: Honoria Waynflete claims that she broke up with Lord Whitfield after he strangled her bird to death. It turns out that she killed the bird, and he broke up with her because if this.
- Woman Scorned: This turns out to be the motive. Honoria Waynflete still hasn't forgiven Whitfield for breaking up with her, and all the murders are part of a spectacular revenge plot to get him hanged.
