Talise knows more about the ocean than any kid in Topsea. Any adult, too. As the best—and only—bathymetrist in Topsea, Talise is able to predict important things about the sea, like the next tide (Severely Low with a threat of Wildcard) or the arrival of Seaweed Season. What she can't predict, however, are her classmates' behaviors. Sometimes it's as if they're speaking different languages. When Talise discovers a mysterious message in a bottle, her classmates believe it must have been sent by someone stranded on a deserted island. (Not to be confused with a dessert island.) And, by the way, has anyone seen the lighthouse keeper recently...? But Talise is convinced the message is meant for her. And it's telling her to build a boat. Everyone seems to think Talise is just being silly. Even Talise isn't exactly sure why she has to build the boat. And who keeps sending those cryptic messages in a bottle, anyway? All Talise knows is that she'd better finish building her boat fast,...

Welcome to Topsea, the strangest place you'll ever visit. In this town, the coves are bottomless and the pier has no end in sight. There's a high tide and a low tide... and a vanishing tide. Dogs are a myth, but mermaids are totally real. And seaweed is the main ingredient in every meal—watch out, it might just start chewing you back! New kid Davy definitely thinks Topsea is strange. His mom keeps saying they'll get used to life in their new town—it's just the way things are on the coast! But after his first day at Topsea School, Davy finds himself wondering: Why is his locker all the way at the bottom of the school swimming pool? Why can't anyone remember his name? (It's Davy!) And why does everyone act like all of this is normal?! Through newspaper articles, stories, surveys, notifications, and more, follow Davy and the rest of Ms. Grimalkin's fifth grade class through the weird world of Topsea. (Whatever you do, don't make eye contact with the rubber ducks.)