After we began eating, the object of our discussion headed our way, perhaps having heard the Pavlovian microwave bell. He bounced from the recycler wall to the bean trellis, off the side of the Martian quarters, and through both lounges, arriving at a reasonable speed surrounded by a nimbus of male sweat, not too unpleasant.

“Mexican!” He went to the fridge and started to rummage.

“In the pantry,” Meryl said. “Under E, for empañadas.”

“Sí, sí; muchas gracias.” He found the packet and put it in the microwave, and floated in front of it upside down. “I’m not interrupting?”

“Just getting a bite,” she said, “but you can’t eat with us unless your feet are in the right direction.”

“Comprendo.” When the food was ready, he brought it over with a slow reverse roll. We were eating at the table, even though there was no reason to actually set the food down on it.

He sprayed hot sauce into the packet and speared the empañadas with a fork, more efficient than either of us. Without preamble, he said, “Have you thought about Spy not being what he claims to be?”

That was not a big stretch. “In what way?”

“Maybe he’s not an alien at all, hmm? Maybe he’s always been here, waiting for turnaround. To test us.”

“Who?” Meryl said. “Who’s testing us?”

“Earth. Testing our loyalty.”

That sounded bizarre enough. “I don’t get it. How could anybody be disloyal?”

“Be in the pay of the Others?” Meryl offered.

“Well, you know. Not pay.”

“No, I don’t know. What?”

He finished chewing, swallowed, and set his food packet floating just over the table. He folded his hands over his chest. “I’ll spell it out.”

“I’m all ears,” she said.

“First, how possible is it that they could chase us eleven light-years, constantly accelerating, and wind up right here at the exact right time—with no evidence of having used any fuel? Without our detecting them?”

We did detect something, I thought; Paul had mentioned an anomaly in the proximity circuits. But I let it be.

“How much more likely is it that they’ve been here all along? That the supposed ‘alien’ was already installed before we got to the iceberg? Tell me it couldn’t be done.”

“Okay,” she said. “It couldn’t be done.”

“Even if it could, why would they bother?”

“Like I say, to test our loyalty.”

“That’s . . .” She didn’t say crazy. “That makes no sense.”

“It seems awfully elaborate,” I said. “They built this alien-looking spaceship, and Spy, and a convincing Other, and kept them hidden for years, to trot them out at turnaround, to see how we react?”

“You’ve got it. That’s it exactly.”

“Moonboy.” Meryl’s voice quavered.

“Where did they hide them for three years?” I persisted.

“Out in plain sight. No one’s gone out to look till now.”