11-year-old Stella has returned home to Shetland to spend the summer with her Grandpa, but it's nothing like she remembers. Grandpa is lost in his grief for Gran, the island is bleak and Stella feels trapped, until she encounters an old woman, Tamar, who can spin rainbows and call hurricanes. With the help of Nimbus, a feisty young storm cloud, Stella begins to learn the craft of weather weaving. But when her cloud brain-fogs Grandpa and The Haken (a sea witch) starts to close in, she realises that magic comes with big responsibilities. It will take all her heart and courage to face the coming storm...