It started as a low, steady, emphatic thrum, like something from a bassoon. Only it wasn’t something he was hearing. It felt more like something tapping at the base of his skull. Henry wondered if the wiring in the walls was shorting out, causing them to vibrate. He placed the palm of his hand against a wall.

Nothing.

Henry got out of bed. He stood in the center of the room and turned around, trying to pinpoint the source of the Pulse. It seemed to be everywhere and nowhere all at once, and now the Pulse slid up in pitch slightly.

Henry moved to the hall. The Pulse was here too. Henry stumbled along, feeling his way. He didn’t want to turn on a light, in case he disturbed someone.

Henry found his way to the kitchen. The Pulse had changed to a series of staccato sensations. Henry felt along the counter to the sink and looked outside the window. The night was as still as it was black. Where was the Pulse coming from?

The light came on in the kitchen, and Henry had to squint to adjust to it.