After Ianthe leads Harrow away from the drunken dinner, both are shaken by the sight of God, Mercymorn, and Augustine kissing. Ianthe tries to kiss Harrow, but Harrow turns away and says her affections lie buried in the Locked Tomb. Ianthe mocks her gently, wishes her luck, and leaves Harrow to carry out the planned attack on Ortus the First.

Harrow sobers herself by forcing alcohol out through her pores, makes a compact bone bomb from her own exoskeleton, and goes to the training room where she expects Ortus to be. Because Ortus can consciously drain thanergy, Harrow designs the bomb to explode into countless small bone shards before he can focus. The attack devastates the room, but Ortus is not there.

Harrow next searches the chamber where Cytherea's body has been lying in state. Cytherea is gone, Ortus's spear is discarded and bloody, and a fresh trail of blood leads away. Harrow reconstructs that someone was stabbed through the heart with Ortus's spear, follows the trail through the engineering levels, and finds Ortus inside the incinerator, impaled through the heart.

Cytherea's corpse appears in the control booth, covered in blood and petals, and activates the incinerator before limping away. Harrow initially considers pursuing Cytherea, but instead chooses to save Ortus. Harrow tears open the incinerator, pushes her Lyctoral bonecraft to an enormous scale against the chemical fire, and drags Ortus out before he burns.

Badly injured, Ortus tells Harrow to use fresh blood wards instead of bone wards because fresh thalergy mixed with thanergy is harder for him and others like him to break. He then seems to address someone else through Harrow, calling that presence love and asking why, long ago, it brought along the beginning of something he cannot finish naming before God, Mercymorn, and Augustine arrive. Later, Ortus claims he does not remember the conversation and admits he sometimes forgets, a confession Harrow recognizes as akin to her own fear of madness.

God and the others investigate, but Cytherea's body cannot be found anywhere on the Mithraeum. Back in her rooms, Harrow replaces her bone wards with blood wards. She overhears Mercymorn and Augustine arguing about their deception, Cristabel, and Cytherea's disappearance, suggesting their alliance is unstable. After Harrow cleans herself and lies down, the Body quietly tells her that the water and sun have risen, and that they will endure.