Aiglamene leads Nona, Pyrrha, Paul, Crux, and Kiriona through dark Ninth House passages toward the Tomb. At a vast cave-chamber blocked by an enormous rock, they find Ianthe Naberius waiting. Ianthe traps everyone except the carried Nona in a sticky field made from fat and mucous membrane, revealing that she has come on her own to stop the Tomb from being opened.

Ianthe and Kiriona greet each other as familiar allies and fellow princes, even wearing friendship bracelets. Ianthe expects Kiriona to help keep the Tomb sealed, but Kiriona instead says John sent Kiriona to open it, kill Alecto, and become John’s cavalier. Ianthe is horrified and argues that John has deceived Kiriona: John loves and needs Alecto, and releasing Alecto will doom them rather than save him.

When Ianthe openly says that John loves and needs Alecto, Nona’s fragile body catastrophically comes apart. Nona bleeds from everywhere and cannot be held together. Paul tells Pyrrha to act, and Pyrrha shoots Ianthe with a rare herald bullet she had been saving for John. Ianthe collapses in agony, and Paul orders the Tomb opened immediately.

The group carries Nona toward the inner entrance. Paul moves the great outer rock and assesses that most traps have already been disabled, but opening the true Tomb requires fresh thanergy. Kiriona, Pyrrha, and Crux all offer themselves. Crux insists that dying for Harrowhark is his right and duty, and after a bitter exchange in which Kiriona confronts Crux over his cruelty to Gideon Nav, Kiriona kills Crux. His death activates the mechanism, and the final rock begins to open.

Inside, Nona remembers John showing Alecto the Tomb: the glowworms, the salt water, the outcropping, and the hard marble resting place. Nona moves the failing body through the water and sees Alecto’s chained body, with Harrowhark asleep within it and Anastasia’s bones hidden nearby. As Nona reaches the body, Nona’s identity slips fully toward Alecto, and Nona falls onto Alecto’s icy breast.