On a whimsical Irish isle, an orphaned boy named Tomás discovers a new world of friendship and wonder when he's adopted by Maire O'Donnell. As he navigates his new life, Tomás finds solace in the island's secrets and the kindness of its creatures, including a lost baby pup seal he names Smudge. But when tragedy strikes, Tomás must confront the darkness that threatens to tear him away from the family who loves him, and find a way to bring light back into his world - just as rainbows can shine around us all.