Miss Marple investigates the murder of Heather Badcock, who consumed a poisoned cocktail apparently meant for American film actress Marina Gregg, Heather's idol. As Marple investigates, she discovers dark secrets in Marina's past, secrets which also link to other seemingly innocent citizens of St. Mary Mead.
The title of the novel comes from the poem "The Lady of Shalott" by Alfred, Lord Tennyson. The character of Marina Gregg is generally assumed to be based on the American actress Gene Tierney—and the central plot points based on events in the life of that actress. Christie herself denied this and insisted the similarity was a coincidence.
The story has been adapted three times for the screen, with Angela Lansbury (1980), Joan Hickson (1992), and Julia MacKenzie (2010) playing Miss Marple. For examples from the 2010 adaptation, see Marple.
The Mirror Crack'd from Side to Side contains examples of the following tropes:
- Adaptational Name Change: A slight one in the 1980 movie, where Heather Badcock surname is spelled "Babcock."
- Asshole Victim: Heather Badcock selfishly sneaked out of her hospital wing, which was quarantined for rubella, in order to meet Marina Gregg, her favorite movie star, inadvertently infecting the pregnant Marina with German measles and ruining her life and the life of her unborn child.
- Beneath Suspicion: Marina successfully makes herself look like the intended victim, taking her off the suspect list completely.
- Blackmail: Done by Giuseppe. He is shot after a trip to the bank. Christie always kills off her blackmailers.
- But for Me, It Was Tuesday: Jason uses this explanation when asked about the "previous relationship" between Marina and Heather. He explains that Heather was a fan of his wife's, and as a result, it was a big deal for her to get Marina's autograph. However, Marina has done hundreds of receptions with fans and signed thousands of autographs, so she simply has no memory of the event Heather described of one more autograph seeker among thousands. Subverted, in that Jason is well aware that while Marina didn't remember Heather specifically, the earlier meeting was even more significant to her than it was to Heather.
- Complete-the-Quote Title: No mirror plays a significant role in the mystery; the allusion is to the line of the poem that follows the quoted line:The mirror crack'd from side to side;
"The curse is come upon me," cried
The Lady of Shalott.
- Driven to Suicide: The killer is found dead of an overdose after The Reveal. It is implied that this was actually orchestrated by her husband, to prevent further murders and to save her from suffering further.
- Honorary Uncle: Inspector Craddock starts calling Miss Marple "Aunt Jane" which he doesn't in any of the other books he's in.
- It's All About Me: Heather Badcock is a non-villainous example of this. She isn't mean, and actually goes out of her way to do nice things for other people, like rescuing Miss Marple after a nasty fall or taking in a homeless family. However, she is incapable of recognizing that her actions affect other people or that what something means to her might not be the same for other people involved. The primary example of this was that when she got sick, she didn't recognize that the doctor's instructions to "Stay in bed and don't go out to meet people" might not have been just for her benefit
- Let Off by the Detective: It is subtly implied that Marina was poisoned by her husband to save her from public disgrace and prevent more murders. Miss Marple suspects this is the case, but keeps quiet.
- Literary Allusion Title: The title is from the poem The Lady of Shalott by Alfred, Lord Tennyson. It's also quoted within the novel.
- Little Old Lady Investigates: Miss Marple, as per usual. Her doctor even recommends that she find a murder to solve because she's getting a little blue and depressed— and investigating does indeed perk her right up.
- Medication Tampering: When Ella Zielinsky uses some medication in an inhaler and makes the mistake of trying to blackmail the murderer. The next time she uses her inhaler, she gets a lungful of Bitter Almonds.
- Mercy Kill: Implied to have been done to Marina by her devoted husband Jason at the end.
- Murder by Mistake: Heather's murder appears to be a misdirected attempt on Marina's life. In fact, this trope is inverted here, because Heather was killed on purpose by Marina herself.
- Never One Murder: After murdering Heather Badcock, the killer also offs Ella and Giuseppe when he tries to blackmail the culprit.
- Red Herring: But of course!
- An eyewitness noticed a look of horror or shock on Marina Gregg's face when she glanced at the stairwell, and much time is spent trying to figure out who was coming up the stairs, and why would they have inspired such a look? The source is not what Ms. Gregg saw, but what she heard.
- Marina Gregg's past life is explored in some detail, including several marriages and adopted children that she foisted off to others when she was expecting a biological child. One of the full-grown children was at the party, and Marina didn't even recognize her. The woman is understandably bitter, but she's not the killer.
- Related in the Adaptation: The BBC Miss Marple adaptation of the book seem to mistake Dermot Craddock as Miss Marple's actual nephew (despite the two being depicted as strangers in A Murder is Announced), rather than an honorary one (see Honorary Uncle above). When Slack advises Craddock to speak to Miss Marple, he tells him that she's his aunt. Later on, Raymond West refers to Dermot as cousin. Same about 1980 adaptation.
- Ripped from the Headlines: The plot is remarkably similar to the real-life tragedy of Gene Tierney, who contracted rubella while pregnant, resulting in Daria being born premature, deaf, blind, and severely mentally disabled. These problems contributed to (or, perhaps, outright caused) Tierney's own depression and bipolar disorder. About a year later a woman approached Tierney at a party and said that she had sneaked out of her marine base, under a rubella quarantine at the time, to meet her when she appeared at the Hollywood Canteen, a wartime club that catered to service members where Hollywood stars would appear. Tierney simply stared at the woman, then turned and walked away. She later wrote, "After that I didn't care whether ever again I was anyone's favorite actress." It should be noted, however, the Christie was asked about the similarity and claimed she'd never heard about Tierney's story until after The Mirror Cracked was published.
- Sanity Slippage: After witnessing a death at close quarters, Marina Gregg is understandably shaken, and the Paranoia Fuel mounts as threatening notes appear on her property and poisons appear in her coffee. The whole thing is an act to defer suspicion from herself, but between her true guilt over the murders and the flashback to a nervous breakdown, her sanity really is crumbling, until she either took an overdose or her husband administered one to simply end it all.
- Society Marches On: Marina's child being disabled would still be a great blow to parents today, but in the time the novel was written, such children were removed to institutions almost immediately and may have had almost nothing to do with their families. The loss is almost as if the baby had not survived at all. It also isn't lightly mentioned that the child even existed.
- Starter Marriage: Marina Gregg's first husband Arthur Babcock. He was a realtor who just wasn't prepared to keep up with the lifestyle of a Hollywood star.
- Sympathetic Murderer:
- Heather was unwittingly responsible for giving Marina German measles and causing her only biological child to be born with birth defects. Marina suffered a breakdown as a result, and when Heather turned up telling with pride how she had snuck out of quarantine to meet her, Marina flew into a rage and poisoned her in the heat of the moment.
- Jason Rudd is implied to have killed Marina himself, to stop her committing more murders and to save her from public disgrace while her stability steadily deteriorated.
- A Tragedy of Impulsiveness:
- Marina poisoned Heather in a fit of murderous rage. If she had not had the means to do so immediately at hand, she probably would have had time to calm down, and the tragedy would have been averted.
- The incident at the root of the whole matter also counts. Had Heather listened to her doctor, it's likely Marina would never have contracted German measles and would have delivered a healthy baby. But she just had to get that autograph...
- Typhoid Mary: Heather was perfectly well after being treated for German measles but she was still highly infectious to the point that she was under ordered bed rest until she was safe to be around other people. She ignored this and infected Marina when she was pregnant.
- Ugly Guy, Hot Wife: Marina, as an actress, is still very attractive despite her age. Her husband, Jason Rudd, is frequently described to be ugly and looks like a clown.
- White and Grey Morality: Both the victim and the murderer are sympathetic, but both of them have fatal flaws that collectively bring about the tragedy. Heather failed to recognize how her actions would destroy Marina's happiness, and Marina poisoned her in a fit of rage without thinking.
- Womanchild: Marina Gregg is beautiful, a great actress, and when she turns on the charm she's absolutely captivating, but her husband is almost a full-time manager because her moods dip so completely from euphoria to despair, and she's very bad at imagining the future.
The 1980 film adaptation The Mirror Crack'd has examples of:
- Adapted Out: Marina's butler Giuseppe isn't in the Angela Lansbury adaptation.
- Blackmail: Attempted by Ella Zelinsky. She calls up people left right and center to tell them she saw them poison Heather's drink. She eventually reaches the correct person, and gets killed for her pains.
- Hollywood Old: Having Angela Lansbury, famous for starring in Murder, She Wrote, play Miss Marple in the film might seem like a very logical move. However, back then, Lansbury by her own admission was 20 years too young for the role.
- Never One Murder: After murdering Heather Badcock, the killer also offs Ella Zelinsky when she tries to blackmail the culprit.
- Passive-Aggressive Kombat: Played for laughs, as Marina (Elizabeth Taylor) and Lola (Kim Novak) exchange hilarious strings of snide insults.Lola: You seem lovely, as always. Of course, there are fewer lights on than usual. In fact, any fewer, and I'd need a seeing-eye dog.Marina: Oh, I shouldn't bother to buy one, dear. In that wig, you could play Lassie.Lola: Same adorable sense of humor. And I'm so glad to see that you've not only kept your gorgeous figure, but you've added so much to it!Marina: What are you doing here so early, dear? I thought the plastic surgery seminar was in Switzerland.Lola: Actually, darling, I couldn't wait to begin our little movie. You know the saying: once an actress, always an actress.Marina: Oh, I do know the saying. But what does it have to do with you?Lola: Cute angel. So do tell. How does it feel to be back, after being away so long?
Marina: I've always thought of Lola as one of my oldest, oldest friends.