It's been five years since a hurricane ravaged Eliza Marino's life and home in her quiet town on the Jersey shore. Now a senior in high school, Eliza is passionate about fighting climate change-starting with saving Clam Cove Reserve, an area of marshland that is scheduled to be turned into buildable lots. Protecting the island helps Eliza deal with her lingering trauma from the storm, but she still can't shake the fear that something will come along and wash out her life once again.

When Eliza meets Milo Harris at a party, she tries to hate him. Milo is one of the rich tourists who flock to the island every summer. But after Eliza reluctantly agrees to give Milo surfing lessons, she can't help falling for him. Still, Eliza's not sure if she's ready to risk letting an outsider into the life she's rebuilt. Especially once she discovers that Milo is keeping a devastating secret.