Dark clouds are rolling in, and a big thunderstorm is right outside the window. Sudden loud noises can be startling, and the bright flashes of lightning make Henry jump. His enormous dog, Mudge, is even more frightened. Every time the thunder crashes, poor Mudge just wants to hide away where it is quiet and safe. Henry knows he needs to help his best friend feel better until the wild wind passes. When Mom suggests heading down to the basement to build a cardboard castle, a scary afternoon turns into an exciting indoor adventure. Working together, Henry and his family find the perfect way to stay busy and forget all about the storm outside. This comforting and relatable story shows how creativity and family support can chase away the thunderstorm blues.