This is basically a Sherlock Holmes retelling, set in de Bodard’s Xuya universe of short stories and novellas, where Watson is actually a sentient ship, and the mystery involves a body dumped into the equivalent of hyperspace, through which humans can’t travel without a ship to protect them and a cocktail of drugs (served in teas, traditionally, though presumably the format doesn’t necessarily have to be a tea) to keep them from going insane.
Of course, the ship, The Shadow’s Child, is less blindly fascinated by the Holmes character (Long Chau) than Watson is in the original stories, and there’s a certain friction between them throughout. The ship doesn’t like Long Chau’s attitudes (she can be abrasive) and is suspicious of her past. The Shadow’s Child has her own tragic past, in which she lost her crew, her family, in an accident — in those deep areas of space that the mindships are able to navigate and from which humans need protection. Naturally, the mystery — and Long Chau’s incisive commentary on her understanding of The Shadow’s Child — end by drawing the ship into the space she fears, in order to prevent further tragedies. Likewise, there are links to Long Chau’s own history and her past disgraceful involvement in the disappearance of a young woman she was tutoring.
Ultimately, the story is perhaps less about the actual mystery and more about that interplay between the two personalities — and The Shadow’s Child eventual decision to face her fears in order to rescue Long Chau and another human, at the conclusion of the mystery. There’s definitely room for more in this world (of course, since it’s part of a whole series of not-necessarily-connected stories) and with these characters: I’ll be interested to read whatever might come of that in future.