There was no debate, to Turk's relief. Dr. Dvali used a pocketknife to cut off a corner of the bedsheet, which Turk tied over his nose and mouth. Turk took the vehicle's keycard from Mrs. Rebka while Lise volunteered for door duty.

"Don't stay out any longer than you need to," she said.

"Don't worry," he said.

* * * * *

The sky was blue, made chalky by the ash that gave the air a sour, sulfuric tang. No telling what this was doing to everybody's lungs. If the dust contained alien spores—which was what all the talk seemed to imply—might they not take root in the moist interior of a human body? But they didn't seem to need much moisture, Turk thought, if they could grow on the paved street of a desert town in a dry September. In any case, there had been no reports of purely ash-related deaths. He shook off these concerns and tried to concentrate on the task at hand.

He felt lonely as soon as he stepped outside. The motel parking lot was a paved half-moon with an empty ceramic fountain in the middle of it. Beyond it was the main street, really just a stretch of Highway 7 heading into the Rub al-Khali. Across the street there was a row of one-story brick commercial buildings. All of this was ash-coated, windows dust-encrusted, traffic signs and billboards rendered illegible. The silence was unbroken.

The Fourths' vehicle, recognizable by its boxy shape and sprung-steel wheels, was parked a dozen yards to Turk's left. He stood a moment and looked back at Lise, who was holding the door open a crack. He gave her a little wave and she nodded. All clear. Onward.

He took long deliberate steps, trying not to stir up too much dust. His shoes impacted the drifted ash and left finely-detailed prints under chalky clouds.

He reached the car without incident and was only slightly unnerved by the distance that had opened up between himself and the room where Lise was waiting. He used his forearm to brush a layer of ash off the rear of the vehicle, the baggage compartment where the groceries were stored. He took Dr. Dvali's keycard out of his pocket and applied it to the security slot. Tendrils of dust rose up around his hands.

He paused and lifted the cloth that covered his mouth long enough to spit. The spittle plopped inelegantly on the surface of the ash-covered sidewalk, and he half expected something to rise up from beneath, like a fish rising to bait, and snatch it away.