When a catastrophic hurricane devastates Stone Cove Island, a quaint New England resort community, everyone pulls together to rebuild. Seventeen-year-old Eliza Elliot volunteers to clean out the island's iconic lighthouse and stumbles upon a secret in the wreckage: a handwritten letter. On first glance, it hardly makes sense. But the longer Eliza studies it, the more convinced she becomes that it's an anonymous confession to a 30-year-old crime: the unsolved murder of a local teen named Bess Linsky.
It's always been just Wren and her mother, Hannah. But when Hannah receives a reporting assignment in Greenland for six months, Wren is shipped off to Hardwick Hall: Hannah's alma mater back East, which she's refused to discuss for as long as Wren can remember. Wren tries to befriend her suitemate, Honor, but Honor looks right through her as if she isn't there.