Excerpt from The Last Boy and Girl in the World by Siobhan Vivian, plus links to reviews, author biography & more

Back in the old days, Aberdeen was primarily a countryside vacation destination for the rich residents of Waterford City, thirty miles downriver. It was cabins and summer cottages and pine groves. People swam in the summer, skied and ice-skated in the winter. My dad even has a vintage postcard showing people in old-fashioned bathing suits, striped umbrellas, and canvas beach chairs, enjoying our beautiful riverfront.

A hundred years later, the seniors of Aberdeen High School still swam in the exact spot the tourists once flocked to, where the bank stretched as wide and flat as an ocean beach, complete with sand that glittered in the sunshine. This wasn't the only swim spot in Aberdeen, but it was the best. Except it wasn't as perfect as the old postcard because of the long-abandoned lumber mill that anchored the end of the beach.

The spot designated for juniors, where I spent nearly every day last summer, was a quarter mile upstream from the senior spot. The beach there wasn't pure sand like the seniors had, more a mixture of sand and dirt and pine needles. You always had to have a blanket down, but it was still nice. A rope swing looped around a fat branch of a tree that grew sideways out over the water. I'm not sure who put it up. It had been around forever.

Last summer, hardly any of the other girls tried it. They were scared the rope would break or their bikini tops would fly off when they hit the water. But after a couple of swings on the first sunny day, I had it down. Which knot to anchor my hands on, exactly when to let go so I'd hit the deepest part of the river, where the water was the coolest. I even took to screaming out something dumb to make everyone laugh whenever I'd make the plunge. Like this one time, I shouted "Super-absorbency!" because Elise had just admitted that she'd once worn a tampon and a pad while swimming at a church retreat, because she feared leaking in the water. The other girls there that day had no idea what I was talking about, but they laughed just the same. The boys shook their heads or groaned. They never knew what to make of me.

The sophomores and freshmen were relegated to a swim spot even farther upstream, near the highway overpass. They had to pull weeds to clear a place for their towels and pick up the trash tossed out of passing cars. The location sucked for those reasons, plus there were tons of plants, slimy reeds, and other crap you didn't want touching you when you swam.

Anyway, that's where we were told to show up for sandbagging duty.

Morgan parked her car near the overpass and we followed the flow of students toward two dump trucks full of sandbags and a rapidly growing group of volunteers. Obviously, other school groups besides Key Club had been summoned to help. Adults came, too. People's parents, off-duty policemen, my second-grade teacher, Mr. Gunther. Even Mayor Aversano showed up, dressed like a complete tool in a suit shirt and dress slacks, with his slicked-back hair. He did have enough sense to swap his dress shoes for a pair of work boots, but I still rolled my eyes.

At exactly seven thirty, Sheriff Hamrick climbed up on one of the dump truck beds, clicked on his bullhorn, and asked everyone to gather around. Then he extended a hand to the mayor and Aversano's dress pants stretched dangerously tight over his butt as he lunged up. Aversano took the bullhorn and started talking but no one could hear him. Sheriff Hamrick had to lean over and show him the trigger to press to make the thing work.

I laughed. Hard. Morgan clapped her hand over my mouth.

"Thanks, everyone, for coming out today. Obviously, we're hoping that the weather forecasters are wrong, the way they tend to be about ninety-eight percent of the time."

A few adults chuckled at that lameness. I remember thinking, hoping, that I would never turn into the kind of person who thought weather jokes were funny.

Excerpted from The Last Boy and Girl in the World by Siobhan Vivian. Copyright © 2016 by Siobhan Vivian. Excerpted by permission of Simon & Schuster Books for Young Readers. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.