When Kendra Kandlestar and her companions went in search of the Box of Whispers, they eventually arrived at the legendary Castle of Krodos. The enormous stone fortress had been constructed in ages long past by a clan of giants, though when Kendra and her fellowship reached the castle they were to discover that its former inhabitants had long disappeared. Indeed, the castle walls were pitted with holes and many of the towers had been toppled, as if the place had been the site of a terrible battle.

At first, the Eens could not find entry into the castle, being too small to reach the many holes. Eventually, they discovered a riddle door that offered them a way inside—if only they could solve its puzzle. This job was left to Professor Bumblebean.