In a tangled thicket beneath the first arched bridge was a man I knew. I recognized him from the bold, dark tattoos that covered his face and neck. His name was Ulan. He had been one of my mother’s engineers, the one who developed materials strong enough to withstand the forces exerted by her experimental engines. I remembered him most by the booming quality of his laugh, the strength of his hands, the way he would spin me around and fling me across the workshop while I shrieked with laughter and my mother rolled her eyes in annoyance. He had little sisters and brothers and nieces and nephews on Earth, all living aboard one of the floating cities in the Pacific that had been admitted into the Councils when Ulan was a child. His mother used to send him recorded messages of the entire family grinning and waving and shouting hello. I had been so jealous of them—it looked so fun, to be there on the sea surrounded by friends and family, so different from the life aboard House of Wisdom, where there were few children, and my parents rarely had time to play with me.

I had never wondered how Ulan died. I had never thought about him at all.

“Move,” said Dag. “Keep going.”

His voice was gruff, but I thought I heard, for only a moment, the slightest hint of something almost like pity. I reached ahead, found a metal rail to grasp, pulled myself past Ulan. I wanted to say his name aloud—to tell somebody, anybody, that he had been a person I knew, that he had a family who had loved him and missed him. I could not make a sound.

On the other side of the bridge, I followed Zahra upward, upward, while the others trailed behind. When the girls reached the bridge, Ariana shrieked at the sight of Ulan’s face tangled in the gray leaves, and that shout hit me like a blow to the chest. I heard her scream, and echoed with it I heard all the others, the screams and pleas and desperate, gurgling gasps that filled my nightmares.

I closed my eyes, but it didn’t help. Ulan’s face was there, even in the darkness. I could not move. They had screamed, the infected and the dying. They had screamed as panic ripped through every person aboard, shouted and cursed and thrashed, clawing at their own skin and scrabbling for phantoms moving through their bodies. I had never forgotten, but I had always been able to push them down, to muffle them, if not ever truly silence them. Voices over the radio joined with the chorus from the past. I couldn’t move. I couldn’t open my eyes. I would only see them again, all the dead, their faces shriveled and inhuman.

“—the fuck is he doing?” Henke, angry.

“Is he having some kind of fit?” Panya, concerned.