“Mom, if you want to be down by the road, I’ll take you there.”

Lillian laughed. “That’s what the car says! Isn’t it? ‘I’ll take you there.’ Isn’t that what the cars say?”

He nodded. “Yes, that’s what the cars say.”

“You know,” she said, “I could use one of those. Old lady like me, car like that is a dream come true. Mobility! I’d just need some help getting into it. Do they build one with a ramp?”

“I don’t know,” her son said. “I’m sure they have something like that in the works.” She had a point, he thought. The Arrival was perfect for old folks who could no longer pass their driving tests. And even for those that still had them, an autonomous car would be a godsend. Take backing up out of parking spots. No more trying to turn your stiff neck around to see where you were going. No more bumping into the car behind you.

“You want to watch the cars go by?” he asked.

His mother nodded.

“Okay, let me take you down to the end of the driveway.”

“If it’s no trouble.”

“Mom, I’m here.”

“Okay, then,” she said.

As he pushed, one of the wheels squeaked as it turned. “Need a little oiling there, Mom,” he said. He wheeled her across the porch, down the ramp, and found her a spot on the sidewalk where she could watch the world pass by.

“Now,” he said, “if you have to go to—”

“I’m good for a while,” she said. Then, whispering, she said, “I’m wearing a—”

“It’s okay, Mom. I don’t have to know everything.”

“You remember him getting on the ferry?” Chief Bridgeman asked the young, blonde woman whose name, he had learned, was Annabelle Harper. She was twenty-seven, from Boston, and worked with an agency that handled special events.

They were standing at the Garrett Island ferry dock, which, at the moment, was empty. The ferry had departed for the mainland more than an hour ago and was probably already getting ready for a return crossing, although given that regular cars were banned, it would be mostly empty. A few walk-ons, at best, a few with bicycles.

“I remember him,” she said. “I chatted everyone up a little as they were getting on.”

“So you’re sure this Clyde Travers boarded?”

She nodded. “But I never saw him get off.”

“Maybe he walked past you without you noticing,” Joe suggested.

Annabelle shrugged. “Like, it’s possible. But I don’t think so. I talked to Fay, who’s working the registration desk at the event site? She said he never picked up his ID tag or his leather case.”

“You mean the pouches they gave out with the press kits?”