A fantasy/mystery novel by Creator/DianaWynneJones. David, forced to spend his school vacation with his guardians, who he dislikes, accidentally releases Luke [[spoiler:(Loki)]] from prison, and then has to protect him from Luke's family, who are after him to give back something he stole.
!! Tropes featured include:
* AdultsAreUseless: Played straight, then subverted. Most of David's relations are willfully oblivious to the supernatural events playing out under their noses, but Astrid eventually becomes useful, if not downright involved, and of course there is the solicitor down the street...
* BeautyEqualsGoodness: [[spoiler:Astrid is described as "quite pretty" when she's first introduced, in contrast to David's other, ugly relations. By the end of the book, she and David have become very close, she helps David achieve his goals, and David is actively looking forward to living with just her.]]
* BeCarefulWhatYouWishFor: On a shopping trip David wishes something interesting would happen, like a fire. [[spoiler:Luke offers to set one in a nearby building, and David is shocked to realize that he can actually do it and that people are now in danger]].
* BigEater: Luke, who at one point downs multiple ice cream sundaes. [[spoiler:Which makes sense considering his long imprisonment and his mythological exploits.]]
* DefrostingIceQueen: Astrid dislikes David's family just as much as he does, and when they realize this they start to get along a lot better.
* EvilUncle: It turns out David's uncle and cousin have been stealing money that was rightfully David's and using it for their own illegal purposes.
* GettingCrapPastTheRadar: [[spoiler:In the myths, Loki once accused Frey and Freya of BrotherSisterIncest. They appear disguised as a married couple. In her memoins, DWJ recalled a close reading editor realizing that Astrid and Thor were having an affair. It almost stopped the book's publication.]]
* JustWhistle: Luke appears when David strikes a match. [[spoiler:This is used to trap him.]]
* LockedOutOfTheLoop: David can only find what Luke stole if he doesn't know what it is.
* MeaningfulName: [[spoiler:Luke, Mr. Chew, Mr. Wedding, and the Frys.]]
* PalsWithJesus: Pals with [[spoiler:Loki,]] rather.
* ParentalAbandonment: David's parents are dead and his guardians are spiteful and neglectful.
* [[spoiler:ReallySevenHundredYearsOld: Luke]]
* [[spoiler:PlayingWithFire: Luke]]
* TheTrickster: Luke.
* [[spoiler:WomanScorned: The ultimate driving force behind the plot.]]