In Michaelmas term at Cambridge, Alice Law resolves to retrieve the soul of Professor Jacob Grimes from Hell. The choice is as professional as it is personal: her dissertation and future depend on him, and she carries secret guilt for a lab catastrophe tied to her own negligence. She studies dangerous Tartarology, assembles supplies, and draws a transport pentagram to bargain with the Lord of Death. Peter Murdoch, a brilliant, habitually unreliable peer, interrupts, revises her circle to carry two, and insists on joining. They accept the entrance price—half their remaining lifespans—and descend.

They emerge onto ashen plains beneath a blood-red sky, glimpse the living world through a Viewing Pavilion, and press on to the Fields of Asphodel. An offering draws four undergraduate Shades from a long-ago lab fire; the students confirm Grimes has already moved ahead toward the courts. At a towering bone wall, queues of Shades block passage. Alice and Peter climb over; Peter freezes mid-ascent and must be coached through. From the top they see the courts’ non-Euclidean churn and commit to a systematic descent to catch Grimes before reincarnation.

Exhausted, they camp and spar about stolen fellowships and a summer trip with Grimes, then agree to trust each other. As the wall dissolves, Hell reconfigures into a Gothic campus—their world reflected back. In the First Court, Pride, a frigid library demands a definition of the good. George Edward Moore shepherds them through rules and gossip, even trying to conscript them. Alice refuses his premise, drawing him into an infinite regress, and they slip out—finding, impossibly, that they have advanced without submitting to judgment.

At the Lethe, the river of forgetfulness, Alice nearly surrenders her self until Peter anchors her with a catechism. Recognizing the terrain’s hyperbolic geometry, they keep to the riverbank. A pack of chalk-stitched bone hounds attacks; the creatures recoil from Lethe’s spray, proving another magician is working in Hell. When chalk sigils sink into silt, they learn pentagram magick fails unless insulated by blood. Rattled, they push on to Desire, a shabby student center where Shades loop through compulsions. A storm drives them out—and into another bone-pack assault. Alice discovers Lethe water dissolves the constructs but tumbles into the river. She surfaces intact, revealing immunity granted by a living pentagram Grimes tattooed on her arm in Venice—a breakthrough that brings perfect recall and lifelong harm.

Their fragile camaraderie fractures when Alice finds a worked organic-exchange spell in Peter’s notes that pairs Grimes’s name with her own. Old ambivalence spirals into fresh distrust. Soon after, a celestial Weaver Girl offers a prisoner’s-dilemma test. Peter chooses together; Alice, panicking and resentful, chooses alone. The Weaver binds Peter—until bone-things swarm. A masked boatman barrels in, spritzes Lethe, and rescues them both. Unmasked, the boatman is Elspeth Bayes, a long-lost Cambridge magician.

Aboard the patchwork Neurath, Elspeth names their hunters: Nicomachus and Magnolia Kripke, sojourning magicians who animate bone rovers and travel with their dead child, Theophrastus. She explains that dying in Hell annihilates the soul, and demonstrates blood-chalk magick by healing Peter and helping duplicate a Perpetual Flask. She frames a larger race for a Dialetheia—a True Contradiction said to unlock escape—but withholds her leads. Alice later attempts to trap Elspeth with a Liar Paradox; Archimedes the cat exposes the circle, Elspeth inverts it to a truth-binding, learns they seek Grimes, and in wrath casts them ashore.

Stranded in Wrath’s bog, they fend off Shades with droplets of Lethe, losing crucial supplies. In Violence, they fall into an Escher trap set with a cuckoo beacon for the Kripkes. Despair cracks their defenses. Alice confesses she caused the accident that killed Grimes. Flashbacks reveal a predatory mentor who tried to coerce her, the rumors that followed, and a system that counseled silence. Peter counters with his own truth: Crohn’s disease he hid, work Grimes stole, and a careless review he gave in anger that enabled catastrophe. In the pit they also admit their original plans—Alice’s Erichtho-inspired binding to compel Grimes’s corpse to speak; Peter’s intent to offer himself, not Alice, in exchange.

As hope fades, Peter refuses closure. Arguing that no system is perfectly closed, he rigs a Hangman’s Paradox escape for one. He bloods the circle and ejects Alice, sacrificing himself. She fails to free him before the Kripkes arrive, and flees as they drain him. Alone, she crosses Cruelty’s desert of purposeless structures into Tyranny, endures the Furies’ scorching inquiry about broken oaths, and enters Dis, the city of traitors. Guided by a nondescript Shade, John Gradus, she tours a bazaar of shortcuts and a workshop of rancor. Gertrude, a severe Shade, rejects reincarnation and invites Alice to a Rebel Citadel that preaches apocalyptic waiting. There, tree-Shades counsel taking root; Alice cannot surrender to stasis. Her panic rouses a Shade who leaps into Lethe; called “Thorn,” Alice breaks a linguistic ward and escapes back to the dunes.

Beyond the river’s reach, a Kripke trap based on Zeno’s paradox seizes both Alice and a starving big cat. As blades prime on the cat’s blood, Alice uses that blood to inscribe calculus that collapses the enchantment. She butchers and eats the carcass, reclaiming bodily urgency and a sharpened will to live. Gradus returns and confesses years pacing the cliff between meaninglessness and oblivion. Choosing the hunt over hiding, Alice crafts bone weapons and armor, snorts magick chalk for perceptual acuity, and smashes the beacon, daring the Kripkes to come.

On high ground above Lethe, Alice sets paradox wards. She dismantles the bone horde, then traps Magnolia and Theophrastus inside a Zeno field by spilling their blood pouches. When Nicomachus arrives, she sprints to a masterwork circle and tethers his soul to a waiting corpse in Cambridge, forcing an overlap of worlds. Archimedes buys a heartbeat; the tether strains; an unseen impulse tips Alice and Nick over the cliff.

In the Lethe’s shallows, Nick’s memories sluice away until he vanishes. Magnolia halts Theophrastus’s killing blow, embraces him, and walks into the river; mother and son dissolve together. A radiant boat arrives for Gradus, who drinks, transforms, and departs. The boat rejects Alice. Lethe eats the tattoo on her arm and unravels her knowledge; she clings to fragments of Peter and almost welcomes oblivion—until Elspeth returns, hauls her out, and cooks her back to life.

Elspeth reveals she found a Dialetheia and that the Kripkes were chasing her. She gifts the paradox to Alice and steers for the horizon, where the shore loops like a projective plane. On the Lord of Death’s island, Alice presents the Dialetheia to King Yama. He summons the Shade of Grimes. Grimes admits he has haunted her dreams and urges her to remain in Hell and study with the artifact, dismissing the living body as a shackle. Alice rejects him. Using Peter’s designs and Elspeth’s chalk, she inscribes a binding; Yama holds Grimes to the circle; the working unspools Grimes to nothing. A door appears and Peter Murdoch steps through, scarred and alive.

Reunited, they bargain the Dialetheia for passage and restitution. Yama restores half their surrendered years and opens a vanishing staircase. They ascend through the dark, accept what grace is offered, and emerge under Cambridge’s stars, resolved to choose one another—and the living world—over the glory that once kept them in Hell.