Gideon the Ninth

by Tamsyn Muir

Book 1 of the The Locked Tomb Series series

Gideon the Ninth by Tamsyn Muir is a genre-bending tale of necromancy, swordplay, and dark humour, set in a deadly contest within a decaying space empire.

Gideon the Ninth by Tamsyn Muir launches The Locked Tomb series with a bold fusion of Fantasy and Science Fiction, blending gothic necromancy, irreverent humour, and a locked-room mystery structure. Set in a far-future empire ruled by death magic, the novel immediately establishes itself as unconventional, sharp, and emotionally charged.

The story follows Gideon Nav, a swordswoman raised on the bleak Ninth House - a place of bone, ash, and devotion to death. Brash, sarcastic, and desperate to escape her miserable upbringing, Gideon is anything but the ideal servant of a necromantic order. When circumstances force her into alliance with her lifelong enemy, Harrowhark Nonagesimus, Gideon is dragged into a high-stakes trial that will determine the future of the Nine Houses.

At its core, Gideon the Ninth is a study in power and dependency. Necromancers and their cavaliers exist in pairs, bound by obligation, sacrifice, and often resentment. This dynamic drives the novel’s emotional tension, exploring how loyalty can blur into exploitation. The relationship between Gideon and Harrow is volatile, defined by rivalry, shared history, and reluctant cooperation, aligning strongly with enemies to allies and toxic partnership tropes.

The plot unfolds as a locked-room mystery, set within a decaying palace filled with ancient trials, deadly constructs, and rival necromantic heirs. As competitors die under increasingly suspicious circumstances, Gideon must navigate secrets, traps, and shifting alliances. The mystery structure rewards close attention, while the rising body count reinforces the story’s gothic horror tone.

Muir’s worldbuilding is dense but purposeful. Necromancy is not a vague aesthetic but a complex system governing society, religion, and warfare. Bones are tools, symbols, and currency. Power is intimate and costly, reinforcing the theme of power at a price that runs throughout the series.

Despite its macabre setting, Gideon the Ninth is frequently funny. Muir’s sharp, contemporary humour contrasts with the gothic atmosphere, making emotional beats land harder. Gideon’s voice - sarcastic, defensive, and deeply human - anchors the narrative, even as it embraces the strange and grotesque.

Gideon the Ninth is ideal for readers who enjoy Science Fiction and Fantasy that challenge convention. With its blend of necromancy, mystery, and character-driven conflict, the novel offers a thrilling, disorienting introduction to a series where devotion is deadly, power is personal, and survival often depends on who you’re willing to sacrifice.

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