The Last Hour Between Worlds

Kembral Thorne is a Hound — a professional investigator and rescuer — and she has finally taken an evening away from her newborn to attend a year-turning party. The night stops being a night off when guests start dropping dead around her, and the house itself begins to fall: with every chime of the clock the party descends into another Echo, a layer of reality stranger and more hostile than the one above it, and a place a person can be lost in for good.

Kembral's investigation has to be run inside that descent, against a clock that is taking the ground away beneath her. Her closest thing to an ally is Rika Nonesuch, a Cat — a thief — and the rival she has spent years measuring herself against. What grows between them over the course of the night is a sapphic romance built out of complicated history and mutual respect rather than sudden attraction, and it is threaded through a puzzle that keeps changing shape as the layers deepen.

Published by Orbit in November 2024, The Last Hour Between Worlds is the first book of The Echo Archives, and the start of a new series from Melissa Caruso, whose debut The Tethered Mage was shortlisted for the David Gemmell Morningstar Award. Reviewers have described it as a puzzle-mystery played out at speed, strongest in its worldbuilding and its escalating structure — one contained catastrophic night, told an hour at a time.