To distract Elsa from a gala being planned in her honor, Anna fills her schedule with fun bonding activities. But what starts as a distraction turns into an adventure when they find a secret door leading to passageways within the castle walls—and the door locks behind them, trapping them inside! Then, as they explore the narrow passages and sealed-off rooms, looking for an exit, spooky things start to happen. Echoing laughter, mysterious patches of cold air, odd arrangements of clothes and furniture...what could be causing all these strange events? With Elsa's powers and Anna's ingenuity on their side, they're more than a match for whatever they find—if they can just find it in time! Packed with humor and heart, Phantoms of Arendelle will keep readers guessing right up until the last page.