“Are you all right, Henry?” It was Aaron’s mother. “Can I get you something?”

Henry turned to face her. The Pulse seemed to fade slightly, but he was still aware of it.

“Do you feel that?” he asked.

“Feel what?”

Henry could see that she had no idea what he was talking about, and he had no idea how to explain it to her. But as they talked, the Pulse seemed to fade to the point of being barely perceptible.

“Nothing,” Henry conceded. “I guess I’m really not used to how quiet it is here.”

Perhaps that was it. Maybe Henry had some low level tinnitus that he couldn’t sense before because of the noise in the city. But when has tinnitus ever changed pitch and rhythm? Henry decided to get checked out once he got back to Cambridge. Just to be sure.

Henry apologized for waking Mrs. Mullins and returned to the guest room. When he was alone, however, the Pulse returned, as insistent as before.

Henry dove into his backpack and snatched his iPod, playing it full volume to drown out the Pulse…