Campbell takes the helm as they motor south from Oswego. Willa is at loose ends without having to drive the boat, but she welcomes the break. After going through the first two canal locks—which are much smaller and easier than the ones on the Welland Canal—she sits beside him and pretends she’s not on fire as he teases his finger along the hem of her cutoffs, tickling her thigh. Taylor moves as far away from them as possible, dangling her legs over the side of the bow while she reads Outlander. Willa pages through the Captain Norm book, trying to find the answer to Finley’s time-travel clue. Upstate New York is brimming with history. Abandoned sanitariums. Crumbling mansions. Revolutionary War graveyards. But somehow she’s sure that none of these things are what Finley had in mind.

Willa ducks under the mast and goes into the cabin, where she uses Taylor’s laptop to pull up a satellite map of the area. Scrolling along the river, she notices a triangular-shaped clearing beside the main road. As she zooms closer, gravel lanes begin to appear. Then a building. Then a screen. She lets out a whoop of delight and scrambles back into the cockpit. “I found it! Taylor, I found it! There’s a drive-in movie theater in Minetto!”

One night, back before they were old enough to drive, Taylor’s dad was taking them to the Nicholsons’ house for a sleepover when they passed the Sandusky Drive-In, which had been closed for all of their lives. The screen tower was falling apart, and chains were strung across the entrance to keep trespassers out, but it hadn’t been torn down yet to make way for a sports complex.

Finley sighed. “I wish the drive-in was still open.”

“Oh man. Did we ever have good times at that old place,” Mr. Nicholson said. “When my friends and I were in high school, I’d park backward so we could sit in the bed of my pickup to watch the movie. We’d open up the cab’s back window and crank the radio. One time I turned my truck box into a cooler and . . . I probably shouldn’t tell you that story. After it closed down, Julie and I took the kids to the Star View Drive-In over in Norwalk once, but Campbell wandered off and we found him asleep in the back seat of someone else’s car.”

The girls laughed, but his story must have planted a seed in Finley’s brain, because one of the first things they did after she got her driver’s license was gather a bunch of people and caravan to the Star View. They parked their cars all in a row and sat in lawn chairs, and Finley opened the back hatch of her Fiat so they could listen to the movie with the volume maxed out.