One summer, a boy named Thomas visits his grandmother at her seaside cottage. She gives him a magnifying glass that once belonged to his grandfather, and with it Thomas explores the beach, turning grains of sand into rocks and dark clamshells into swirling mazes of black, gray, and white. When his grandmother shows him a piece of sea glass, Thomas is transfixed. That night he dreams of an old shipyard and the breaking of a bottle. Could the very piece of sea glass on his nightstand have come from that bottle? For the rest of the summer, he searches for more sea glass and hopes to have dreams that will reveal more of the sea's secrets. A stunning ode to stories and the seaside, this picture book invites readers to imagine the ocean of possibility that lives in every small or forgotten treasure.