When Sam arrives in Foggy Harbor, population 3,230, all she can see is a small, boring town that's way too far from home. And knowing that she's stuck there all summer with her grumpy Uncle Mitch only makes things worse.
 
But when Sam discovers a hidden trapdoor leading to a room full of strange artefacts, she realises Foggy Harbor isn't as sleepy as it seems. With the help of a new friend, Sam discovers an extraordinary secret beyond the fog: an island of unicorns whose fates are intertwined with hers.