Monsters, vampires, and mummies need their gloomy weather in the medieval land of Castleblanca. Hacker, the power-hungry scoundrel, has stolen the weather chip flooding the town with sunshine. A blinding beam of light guards the chip. The Cyberchase kids must come to the rescue and build a lean-to large enough to cast a shadow and allow them to recover the chip. By playing games and solving puzzles the kids acquire parts needed to build the lean-to and restore gloomy weather in Castleblanca!