It's the summer before seventh grade, and twelve-year-old Mack is still learning what life is like without one of their dads. Things have been hard ever since he passed away, and then they’re told they have to spend the entire summer with grandparents they’ve never met before. They should be excited to spend a summer in a house on the beach, but they don't know anyone in Bellevue, and their stomach twists just thinking about all the unknowns living in a new place will mean.

Turns out, there are plenty of kids in Bellevue just like them. And when sharks start disappearing from the coast, Mack and their new friends have a pretty good idea who’s behind it…