“We don’t know who is controlling them or why,” Captain Ngahere said. “We have established that if one of them is disabled, the others pick up the task without any visible communication. We’ve tried to isolate them, to incapacitate them, to stop them. So far we’ve failed.”

My mother took the tablet from the captain. Her hand grew large, momentarily blocking the view, as she tapped a command. “They don’t seem to care that we can watch them. They don’t care that we’re here at all, not now that they have control of the ship. So we can see what they’re doing.”

Her image was replaced by a navigation display, a dizzying array of lines and colors and shapes. I tried to make sense of it, feeling the once-familiar sensation of being too slow to follow where my mother’s mind was leading.

“The hostile force is altering the ship’s navigation constraints. They have disabled the collision-avoidance mechanism. They have reduced the atmospheric correction to zero. They have removed all of the acceleration dampers. I don’t know how they did any of this, but I know the result. They have, in short, disabled every automated and manual component of the ship’s drive system that protects it from a planetary collision. They are going to crash the ship into Earth.”

“No,” I whispered, as though Mum could hear me.

There was a pause, and in the silence Ariana said, her voice hollow, “I thought it was admiring the view.”

“We haven’t been able to regain control of the ship’s navigation and drive systems,” Captain Ngahere said. “Every time we try, they catch up. There’s no delay between our removing one hostile individual and another taking their place. We haven’t been able to disrupt their communication.”

“We have one last thing to try,” said my mother. “We will attempt to incapacitate the hostile force for long enough to put the ship in a stable orbit.”

“Beginning atmospheric quarantine protocol,” the captain said.

They were isolating the air in small sections throughout the ship—but they had known the parasite was transferred through blood, not air. I stared at the screen, trying to understand.

My mother took a breath. “Ready with new course calculation. It’s going to try to reset the navigation every two seconds. It will get through. Once they aren’t stopping it . . . it will get through.”

“Okay.” Captain Ngahere paused, then looked at my mother. “Okay. Shipwide fire suppression protocol.”

“Oh, no,” Baqir murmured. On the recording, an alarm began to sound.

The fire suppression protocol meant oxygen would be replaced by carbon dioxide in some places, argon in others. It was meant to deprive a burning fire of fuel. It was meant to be used sparingly, in closed sections, when fires were raging out of control, only after everybody had been safely evacuated.