Several novels into an impressively creative career, Caitlin Starling remains as elusive to categorise as ever. To many critics, The Luminous Dead (2019) heralded the arrival of a major new voice in science fiction, only for Starling to neatly sidestep into historical drama with her follow-up, effortlessly blending in a dose of horror into The Death of Jane Lawrence (2021). Refusing to be pigeonholed, her latest, Last to Leave the Room, once again puts a few genres and wild concepts in the mixer, and its result is an intoxicating blend of science fiction, horror, paranoia, obsession, and doppelgängers. It might be highly improbable, and you will be scratching your head, but it works perfectly.

The unsettling rumblings pivotal to the background of Last to Leave the Room are incredibly understated and set the scene beautifully. Once I (just about) got my head around its concepts, I was totally sucked into the story. All buildings in the city of San Siroco are slowly sinking a few centimetres every month, and no scientists are able to explain why. At the same time, the internal dimensions of the main character’s basement are expanding (a fact she keeps to herself), and these distorting dimensions are unexplainable and debunk every possible law of physics.

This is a whacky premise for a novel, with the combination of expansion and sinking potentially leading to mass catastrophes of building collapses, roads buckling, or water mains exploding, but Starling deliberately sidesteps these types of distractions which would obviously dominate an action-based apocalyptic style thriller. Instead, she delivers a delicious slow burner, in which characters overlap and morph together. Although we are given brief glimpses of the ‘big picture’, this claustrophobic read is limited to a few characters and is mostly set in Dr. Tamsin Rivers’s flat, her online work meetings or interactions with her threatening boss.

Speculative horror novels need a great hook to suck their readers in, and Last to Leave the Room has a beauty, part of which reminded me of Gus Moreno’s mind-bending but brilliant This Thing Between Us (2021). Tamsin is the head of the research team assigned to find the source of the weird subsidence, working for a shady exploratory tech company that has its own agenda in staying ahead of the curve in the impending disaster. Tamsin is a career-first style of woman and will step on anybody to get ahead but finds herself strangely conflicted when a door (which won’t open) mysteriously appears in the wall of her expanding basement.

Although the pace might be too slow for some readers, I found myself totally absorbed by the internal conflicts of Tamsin and how she managed, her extremely dangerous handler/boss Lachlan, who monitors her emails and every other movement. To say much more about the dynamics of the plot would head into spoiler territory, except things get even stranger when Tamsin discovers an exact duplicate of herself sitting beside the weird new door in her basement. Let the fun begin.

From that moment on, Last to Leave the Room becomes even more intriguing with us entering the world of doppelgängers, Weird Fiction and the (even more) impossible. Around this point, I advise reading this novel even more closely, as you will be desperate for clues of what lies beyond the door, whether the new entrance is related to the buildings sinking, and what the duplicate genuinely wants. Even though creditability is stretched way beyond breaking point, the manner in which Caitlin Starling spins her story is eerily believable, delicately subdued almost, and there are plenty of tricks and traps in the story to catch the reader out.

I had early suspicions about the direction the plot was heading (and was not wrong), but this did not spoil what is a highly enjoyable but delicately low-key, horror thriller. Like with both versions of Dead Ringers, before long you will be questioning who is who, in the deliberately misleading narratives, getting lost in the psychological labyrinth and obsessions of Dr. Tamsin Rivers. If she does not know who she is, we, the readers, have even less chance! I do not claim to have cracked Last to Leave the Room 100%, but had a hell of a fun time trying to decipher its secrets. Confusion is bliss.