Gideon the Ninth Review — Is It Worth Reading?

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Verdict: A locked-room murder mystery inside gothic space necromancy, carried by the best narrative voice in modern SFF, and gated behind a first third that explains nothing on purpose.

Best for: Readers who will trade two hundred confusing pages for a hundred devastating ones, who want a sapphic dynamic that is intense rather than romantic, and who are not put off by an unfinished series.

Heat level: ★☆☆☆☆ (1/5 — romance.io’s “glimpses and kisses”, and in practice not even that)

Rating: ★★★★☆ (4.0/5 — a 4.17 Goodreads average across 196,102 ratings, with a famously high bounce rate)

Tropes: Enemies to lovers adjacent, locked-room mystery, necromancy, gothic decay, sworn bond, found rivals, unreliable comedy, tragic ending, cliffhanger, space opera.

Gideon the Ninth is Tamsyn Muir’s debut and the first of The Locked Tomb, a work of science fantasy published by Tor.com Publishing on 10 September 2019, set in a nine-planet star system where each House practises a different flavour of necromancy, and built on the collision between Gideon Nav — an indentured swordswoman who has tried to escape the Ninth House eighty-seven times — and Harrowhark Nonagesimus, the necromantic heir who owns her indenture and needs a cavalier for a test that will probably kill them both.

It holds a 4.17 average across 196,102 Goodreads ratings and a 4.26 across 80,888 StoryGraph reviews, and it won the 2020 Crawford Award and the 2020 Locus Award for Best First Novel, with Hugo and Nebula Best Novel nominations behind it. It also has one of the most consistent complaints on our entire sapphic fiction list, and it lands in the first two hundred pages. Both halves of that split are worth understanding before you start.

What Is Gideon the Ninth About?

This is science fantasy with a murder mystery inside it rather than a romance, and getting that straight in advance will save you a lot of grief. The setup is a closed-circle puzzle: eight Houses send a necromancer and a swordsman each to a decaying mansion on the First House’s planet, they are set a series of unexplained trials, and then people start dying. What Muir does with that frame is unusual — she refuses to explain the rules of the world before running the plot through them, so you are reconstructing the magic system, the political history and the point of the trials at the same time as the characters.

Gideon is introduced through refusal: she wants out, she has a stack of dirty magazines, she is funny in a register that is aggressively modern, and she has no interest whatsoever in her House’s religion. Harrow is introduced through contempt — she is brilliant, cruel, eighteen years old and carrying something she cannot put down. The novel is told entirely from Gideon’s viewpoint in third person, which matters enormously: everything you are told about necromancy is filtered through someone who never paid attention in class.

What Makes This Sapphic Science Fantasy Work

• Gideon’s voice: The most-praised element by a distance and the thing people quote at each other. It is also the exact reason some readers bounce, which makes it the single most load-bearing choice in the book.
• The genre fusion: A locked-room mystery, a gothic house novel and a space opera running at once. 82% of StoryGraph readers mark it dark, 76% mysterious and 65% funny, which is a combination almost nothing else achieves.
• The Gideon and Harrow dynamic: Mutual loathing collapsing into total devotion, sealed by a vow the Ninth House takes literally. Readers quote “one flesh, one end” the way other fandoms quote proposals.
• The last hundred pages: The most consistent statement in the four and five-star reviews is that the ending is worth the entry cost, and it is stated in almost identical words by thousands of readers.
• The necromancy: Genuinely original system-building — bone, blood, soul and thanergy treated as engineering rather than mysticism.

Book Synopsis

The Ninth House is a dying tomb-cult on a cold planet with two hundred living inhabitants, most of them elderly, and Gideon Nav has spent her life there as indentured labour with a sword and a plan to leave. Her eighty-eighth escape attempt fails like the others, intercepted by Harrowhark Nonagesimus, the Reverend Daughter, who has hated her since childhood.

Then a summons arrives from the Emperor. Each House is to send its heir and one cavalier primary to Canaan House, where they will compete to become Lyctors — immortal servants of the Undying King. Harrow cannot go without a swordsman. Gideon is the only one left. The offer is freedom in exchange for one performance of loyalty she does not feel.

Canaan House is enormous, half-flooded and full of locked doors nobody will explain. The other Houses arrive with their own agendas. The trials have no stated rules. And then the first body turns up. The question the novel spends its second half on is not who is killing them — it is what the test is actually for, and what a necromancer is expected to do with the person who came with her.

My Review

The voice is the whole engine, and it is worth being honest about how divisive that is. Gideon narrates a gothic necromantic murder mystery in the register of a very funny teenager who is not taking any of it seriously, and the collision between the setting’s solemnity and her commentary is what makes the book move. When it works, it is the funniest thing in genre fiction in years. When it does not, readers describe it as aggressively of its moment and grating, and both groups are describing exactly the same sentences.

The second strength is what Muir does with the central relationship, and it is not what the marketing implies. Gideon and Harrow do not fall in love in any way a romance reader would recognise — there is no confession, no kiss and no courtship. What there is instead is an eighteen-year mutual hatred that turns out to have been a form of dependence, formalised by a House vow that means what it says. The book takes that vow literally in the final act, and the result is one of the most devastating endings in recent SFF precisely because it refuses to be romantic about it. Smart Bitches, reviewing as a romance venue, said flatly that this is not a romance, and they are right.

Where it struggles is the opening, and this is the dominant complaint rather than my own impatience — it appears in a large majority of the one, two and three-star reviews and it has three separate mechanisms. First, the mystery structure is withheld: the cast assembles at Canaan House and then very little happens for a long stretch while the reader does unassisted worldbuilding. Second, the terminology arrives undefined — Lyctor, cavalier, thanergy, siphoner, and Houses referred to by number rather than name — and readers cannot build a working model of the magic, with one describing thickets of unexplained jargon so dense it was hard to find the other side. NPR made the same observation from the professional side. Third, sixteen-plus characters are introduced in a rush and tracked by House ordinal, so readers report needing the dramatis personae constantly. Kirkus, which did not star the book, added a narrower reservation: the tight focus means you never learn how anyone outside a necromantic House actually lives.

The expectation worth resetting is the pitch. Lesbian necromancers in space is an accurate description of the furniture and a misleading description of the plot. If you came for a sapphic romance, calibrate hard — Gideon is textually a lesbian, the book is unambiguously sapphic, and the central pairing is not a love story in this volume and does not end happily. If you were worried the humour would undercut the horror, relax: it is genuinely dark, with gore and body horror in StoryGraph’s graphic tier.

My honest note: A book that spends two hundred pages daring you to quit and then justifies every one of them. If you need to understand what is happening in order to keep reading, this will defeat you; if you can tolerate confusion as a texture, the last hundred pages are as good as the genre gets.

Element	In Gideon the Ninth
Central relationship	Gideon Nav & Harrowhark Nonagesimus — indentured swordswoman and necromantic heir, bound by a vow rather than a romance
Core tropes	Locked-room mystery, mutual loathing to devotion, sworn bond, gothic decay, necromancy, tragic sacrifice
Setting	The star system Dominicus — nine necromantic Houses, with the action at Canaan House, a flooded mansion on the First House’s planet
Heat level	1/5 — no on-page sexual content between the leads at all
Series	The Locked Tomb book 1 of 4 — three published, Alecto the Ninth still unpublished with no announced date
Content notes	Graphic gore, body horror and mutilation, murder, torture, suicide and self-harm, child death and infanticide, genocide, child soldiers, terminal illness, corpse desecration, heavy profanity

How Dark and Spicy Is Gideon the Ninth?

A 1/5 on heat, and the honest number is closer to zero. romance.io files it as “glimpses and kisses” but there is no sex scene between Gideon and Harrow, no kiss, and no confession — the Trigger Warning Database entry for the book carries no sexual-content warning of any kind. Gideon’s lesbianism is constant and on the page as characterisation rather than as plot: the dirty magazines are a running joke and she notices women throughout. Book Trigger Warnings does flag an age gap and romantically charged interactions between an eighteen-year-old and a twenty-seven-year-old, and it is worth being clear that this refers to Gideon and another character entirely, not to Harrow.

What is graphic here is violence. StoryGraph’s community warnings put death, violence and gore in the top tier, with suicide, child death and cancer at moderate, and the body horror is sustained rather than occasional. That is the register to prepare for. For the same restrained heat band on this site, The Jasmine Throne and This Is How You Lose the Time War both sit at 1/5 — three books proving that a sapphic novel can be overwhelming with nothing on the page.

Who Should Read This Book?

You’ll likely love it if: you enjoy being dropped into a world without a map, you want a locked-room mystery with real body horror in it, you find modern humour inside gothic solemnity funny rather than jarring, and you are happy with intensity in place of romance.

You may want to skip it if: undefined terminology frustrates you, sixteen characters introduced at once is too many, you need a romance to resolve, or an unfinished series with no publication date for the final book is a dealbreaker.

In short: the highest ceiling on this list and the highest entry cost, and the two are the same design decision.

What Readers Are Actually Saying (August 2026)

Seven years on, the discourse around this book has one dominant subject and it is not the book. Alecto the Ninth, the fourth and concluding volume, is still unpublished as of August 2026 — roughly three years past the autumn 2023 slot Tor originally floated, with no official release date from Tor, Macmillan or Muir. The fandom calls the wait the Alectopause. That is now a live purchase objection for new readers, and it deserves a straight answer rather than reassurance. Alongside it sits an unusually decorated debut record: the 2020 Crawford Award and the 2020 Locus Award for Best First Novel, both won, plus Hugo Best Novel and Nebula Best Novel nominations that it lost — the Hugo, as it happens, to A Memory Called Empire, also on our list. It was not a Lambda finalist. No adaptation has been announced.

Why readers love it (according to the discourse): Gideon’s voice comes first and comes up most, by a distance — readers quote her, and the humour is the single most cited reason people finished. Second, and stated in near-identical words across thousands of reviews, is the last hundred pages; the formulation that the ending is the best hundred pages of anything they have read recurs so often it functions as the book’s real recommendation. Third is the Gideon and Harrow dynamic, with the Ninth House vow as its emblem. Fourth is the originality of the necromantic system, treated as engineering rather than atmosphere. Fifth is Harrow’s backstory reveal, which a striking number of readers name as the moment the whole book reorganises itself. Sixth is the genre fusion — 82% dark, 76% mysterious and 65% funny on StoryGraph is a profile almost nothing else on our list has. The minority view worth flagging cuts directly against the main complaint: a large contingent argues the withheld exposition is the point, that the confusion is Gideon’s confusion, and that the book is designed to be reread rather than understood on the first pass.

What readers argue about and complain about: The first third, above everything. The mechanism has three parts, and it is worth separating them because readers often conflate them. One, no forward plot: the cast assembles and then the mystery structure is withheld for a long stretch, with readers reporting a hundred and fifty pages of nothing happening. Two, undefined jargon: Lyctor, cavalier, thanergy and siphoner are used before they are explained, so the magic system cannot be modelled, and NPR corroborated this from the professional side. Three, character overload: sixteen-plus figures arrive at once and are tracked by House number rather than name, which is the true shape of the complaint usually reported as “the names are impossible.” The fourth theme is tonal — Gideon’s register reads to a real minority as juvenile and very 2019, and those readers find the protagonist grating rather than charming, which is fatal in a single-POV book. Fifth, least frequent: structural whiplash, where the back third accelerates so hard that the two halves feel like different novels. The genuine split is over whether the opacity is craft or carelessness, and it does not resolve — the same two hundred pages produce both the DNFs and the five-star reviews.

The series question everyone should ask first: This is where you need clear eyes. Gideon the Ninth resolves its own murder mystery, but it ends tragically and on a hard cliffhanger that launches directly into Harrow the Ninth. Three of four books are out — Gideon (2019), Harrow (2020) and Nona the Ninth (2022) — and the concluding Alecto the Ninth has no announced release date. Nona was originally conceived as Alecto‘s prologue and grew into a full novel, which is the proximate cause of the delay. If unfinished series are a dealbreaker, this is a real one and you should wait. The counter-argument the fandom makes is worth hearing: each volume resolves its own arc, and if Alecto never arrives the first three do not retroactively become bad. Note also that Harrow the Ninth is structurally far stranger than this book, and a meaningful number of readers who loved Gideon stall there.

The audiobook is narrated by Moira Quirk and runs a little under seventeen hours from Recorded Books, and her character voices are cited by readers as the single most effective way to solve the sixteen-characters problem — if the cast is what defeated you in print, this is the fix.

Prefer audio? Listen to Gideon the Ninth on Libro.fm — the audiobook shop that supports independent bookstores.

Frequently Asked Questions

Is Gideon the Ninth a romance?

No. Gideon is textually a lesbian and the book is unambiguously sapphic, but there is no confession, no kiss and no courtship between Gideon and Harrow in this volume, and it does not end happily. Read it as an intense bond, not a love story.

Does Gideon the Ninth end on a cliffhanger?

Yes, and a tragic one. The murder mystery resolves, but the final act ends in sacrifice and transformation and runs straight into Harrow the Ninth. It is not a standalone.

Is the Locked Tomb series finished?

No. Three of four books are published, and Alecto the Ninth has no announced release date as of August 2026. Each volume resolves its own arc, but the overall story is incomplete.

Why is the first half so confusing?

By design. The magic system, the House politics and the point of the trials are withheld and delivered through a narrator who never paid attention, so you reconstruct the world as you go. Most readers say it clicks somewhere between pages 150 and 250.

How explicit is it?

A 1/5, and effectively zero. There is no sexual content between the leads. What is graphic is violence — StoryGraph’s top warnings are death, violence and gore.

Did Gideon the Ninth win any awards?

It won the 2020 Crawford Award and the 2020 Locus Award for Best First Novel. It was a Hugo Best Novel and Nebula Best Novel finalist and lost both, and it was not a Lambda Literary finalist.

If You Loved Gideon the Ninth, Read These Next

Try A Memory Called Empire for the book that beat it to the Hugo, with the same appetite for a protagonist reconstructing a hostile culture in real time; This Is How You Lose the Time War for a sapphic dynamic built on the same antagonism-into-devotion engine at a fraction of the length; and Plain Bad Heroines for gothic decay, a body count and a similar refusal to hold your hand. More across our Book Reviews and on our sapphic fiction list.

The Bottom Line

Gideon the Ninth set out to put a locked-room murder mystery inside a decaying gothic house in space and narrate it through someone who thinks the whole thing is ridiculous, and three things carry it: a narrative voice with no real competition in the genre, a necromantic system built like engineering, and a final hundred pages that thousands of readers describe in the same awed sentence. Three things hold it back: two hundred pages that withhold their own structure, terminology used before it is defined, and a cast of sixteen introduced by ordinal number. If you can tolerate confusion long enough to be paid out, this is the highest ceiling on our list — just go in knowing the series is not finished. Check Gideon the Ninth on Amazon →

The Eikna Overall Ranking

We rank Gideon the Ninth at 4.0/5 — an extraordinary debut with a punishing first third and a payoff almost nobody disputes.

The Evidence Scorecard

Overall ★★★★☆ 4/5

• ✓ 4.17 average across 196,102 Goodreads ratings
• ✓ Winner, 2020 Crawford Award and Locus Best First Novel
• ✓ Hugo and Nebula Best Novel finalist
• ✓ Most 1-3 star reviews name the same first two hundred pages

Romance ★★★★☆ 3.5/5

• ✓ Scored on the bond rather than a genre arc, as it is not a romance
• ✓ Loathing into devotion is executed with total conviction
• ✓ “One flesh, one end” is the most-quoted line in the fandom
• ✓ No confession, no kiss, and it ends in annihilation

Characters ★★★★★ 4.6/5

• ✓ Gideon’s voice is the most-praised element in every review set
• ✓ 83% of StoryGraph readers report strong development
• ✓ Harrow’s backstory reveal reorganises the whole novel
• ✓ Sixteen-plus figures introduced by House number at once

Writing ★★★★☆ 4.3/5

• ✓ Comedy and gothic horror sustained in the same sentences
• ✓ NPR called it brilliantly original, messy and weird straight through
• ✓ Necromantic worldbuilding is genuinely new
• ✓ Jargon used before it is defined, and Kirkus did not star it

Emotional Impact ★★★★★ 4.5/5

• ✓ The last hundred pages are the book’s most-cited feature
• ✓ 82% of StoryGraph readers mark it dark, 65% funny
• ✓ The final sacrifice lands harder for being unromantic
• ✓ Readers who bounce off the voice feel nothing at all

Heat Level ★☆☆☆☆ 1/5

• ✓ romance.io files it as glimpses and kisses
• ✓ No sex, no kiss and no confession between the leads
• ✓ Gideon’s lesbianism is constant as characterisation
• ✓ Trigger warning databases log no sexual content at all

Ending ★★★★☆ 4/5

• ✓ The murder mystery resolves fully and fairly
• ✓ The final act recontextualises the entire book
• ✓ Widely described as the best hundred pages readers have read
• ✓ Tragic, cliffhangered, and the series is unfinished

Re-read Value ★★★★☆ 4.3/5

• ✓ Built to be reread; the withheld exposition resolves on pass two
• ✓ Planted clues across the trials pay off retroactively
• ✓ Rereads are standard before each sequel
• ✓ The confusing first third is still slow the second time

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