A novel by Creator/DianaWynneJones. The guiding spirit of the star Sirius is framed for a murder and sentenced to reincarnation on Earth in the form of a dog, unless he can come up with the murder weapon (which also happens to be a very powerful MacGuffin).
!!Tropes featured include:
* [[ABoyAndHisX A Girl And Her X]]: Kathleen and Sirius - at least from her perspective.
* AbusiveParents: Duffy - not actually parents; Kathleen is staying with her Aunt and Uncle.
* AmplifiedAnimalAptitude: Sirius can understand a lot more english than most animals. Justified since he's not really a dog.
* BalefulPolymorph: Sirius as a dog.
* BitterSweetEnding: See DeathByNewberyMedal, below. [[spoiler: Sirius achieves his goals and he finds a better home for Kathleen, but the two are separated, possibly forever.]]
* BurningWithAnger: Sirius does this spectacularly as a star, and his eyes do it as a dog.
* CatsAreMean: Starts off this way, but they do mellow out part way through the story.
* CoolOldLady: Mrs. Smith
* DeathByNewberyMedal: [[spoiler: Sirius (again, from Kathleen's perspective--he actually becomes a star again, but he leaves behind his dog-body as a corpse and it's clear that she thinks of him as dead)]].
* EvilMatriarch: Duffy
* FriendToAllLivingThings: Kathleen and Mrs. Smith.
* IWasNamedMyName: Subverted. In a world where stars are actually sentient creatures with godlike powers, Sirius is framed for murdering a dwarf star, and banished to Earth to search for a vital piece of evidence -- and, in the process, forced to be reborn as a mortal... a mortal ''dog'', to be precise. When he is later adopted by a young girl, she mulls over his name for a long time, but eventually settles on "Leo" -- lampshading it later, when she learns about 'The Dog-Star, Sirius' at school, and comments that it would've been a better name.
** Played straighter later in the book when Sirius meets Miss Smith, who is generally presented as wise and perceptive and who quickly decides that she's going to call him "Sirius".
* JerkWithAHeartOfGold: Kathleen's cousins.
* MacGuffin: The Zoi.
* OrphansOrdeal: Kathleen's story, especially after [[spoiler: her father dies because of his escape from prison]].
* PassiveAggressiveKombat: Sol with Sirius' Companion.
* TakingTheHeat: [[spoiler:Sirius]] furiously denies having [[spoiler:killed the victim and thrown the Zoi at the witness]]. But he won't provide an alternate story [[spoiler:because doing so would implicate his Companion]].
* TantrumThrowing: The Castor luminary claims Sirius did this (and aimed to kill) with the Zoi when he discovered Sirius with the body of the young Orion luminary. The problem with this: [[spoiler:A Zoi has to be in someone's hands for him to kill with it, and it was Sirius' ''Companion'' who threw it as Sirius tried to wrestle it out of her hands.]]
* UsefulNotes/TheTroubles: Kathleen's father is an imprisoned member of the IRA.
* TheWildHunt: Sirius in his dog incarnation turns out to be related to them. As Sirius's littermates, so are most of the other dog characters.