This fourth entry and prequel tells the story of Lundy, a very serious young girl who would rather study and dream than become a respectable housewife and live up to the expectations of the world around her. As well she should.
When she finds a doorway to a world founded on logic and reason, riddles and lies, she thinks she's found her paradise. Alas, everything costs at the goblin market, and when her time there is drawing to a close, she makes the kind of bargain that never plays out well.
Seanan McGuire also wrote a short story for the book, "Juice Like Wounds" about how Mockery, Moon, and Lundy battled the Wasp Queen and how Mockery died, made available for free on Tor.com.
Tropes appearing in this work include
- Ambiguously Evil: Lundy's father, who visited the Goblin Market and decided to not go back, believes that the Market is evil and predatory, targeting children, who he believes don't understand true value. He tells Lundy if it were truly the paradise she thinks it is, the doors wouldn't stop appearing once children turned eighteen. Lundy doesn't believe him, believing the Market to be strict in regards to its rules, but never evil. Neither are confirmed to be 100% right.
- Baleful Polymorph: Accumulate debt in the Goblin Market, and you'll slowly turn into a bird. Moon and Lundy both fully transform due to various deals, and there are trees full of bird cages from people who refused to pay their debts. Cheat, steal, and lie, and you'll turn into a full monster.
- Big Sister Instinct: The reason Lundy tried to stay seventeen forever? She couldn't bear to abandon her sister before she was ready to let her go.
- Bookworm: Due to her peers shunning her, Katherine decides from a young age to lose herself in books. In fact, she's so wrapped up in reading that she almost misses her door.
- Bazaar of the Bizarre: The Goblin Market, of course. It was the Trope Maker.
- Chain of Deals: They're not uncommon, as the most bizarre things are dealt with in the Goblin Market.
- Deliberate Values Dissonance: Downplayed, but most of the story takes place in The '60s, and Lundy has to endure sexism. Her second trip to Goblin Market is after she gets fed up with a sexist teacher and wants to go back to a place without so many expectations.
- Downer Ending: Lundy's attempt to stay seventeen forever breaks the Goblin Market's rules, and she's permanently banished. Shortly afterward, she's forced to abandon her family too before anyone realizes she's aging backward.
- Foregone Conclusion: Readers who have read Every Heart A Doorway will know that the story ends with Lundy permanently banished from the Market and stuck with reversed aging due to a poorly considered bargain.
- Genius Loci: The Market itself maintains debts and balances so no one becomes too rich or cheats each other.
- Glass Weapon: One of Lundy's keepsakes from the battle against the Wasp Queen is a glass knife.
- Intangible Price: There's quite a few things to sell and buy around the Goblin Market of this type, and they tend to fetch a very high price.
- Only Known by Their Nickname: No inhabitant of the Goblin Market will actually give their name, as it's a very steep bargain, so everyone goes by other names. The only exception is Moon, who has no real name.
- Posthumous Character: Mockery, Lundy's best friend who dies in the battle against the Wasp Queen, never actually appears in the story. However, her death prompts Lundy to leave for the first time, and later it influences her relationship with her sister Diana. She later appeared in the short story "Juice Like Wounds".
- Reasonable Authority Figure: The Market. It has to hold everyone to the same rules so no one cheats each other. But it is also reasonable about how to go about it, giving a fair amount of leeway to children that decreases as they grow older and know better, and it will only demand what people can realistically give. It also provides food for free as long as no one hoards it. On the other hand, the Market did give Lundy the potion to allow her to age backwards, which broke her own rules, leading to Lundy being banished, which is arguably not "fair value", and both the Wasp Queen and Lundy's father note how predatory it seems that the Market targets only children for its residents.
- Romantic Two-Girl Friendship: Possibly what Lundy and Moon have.
- Work Off the Debt: Basically how the Goblin Market runs. Everything is a system of gift and debt, and anything from doing laundry to making deliveries can work off your debt if you don't have something tangible to give.