From the publisher:
Chaos reigns in the kingdom as the king and queen have died, leaving no heirs. The heroes are commissioned to go into the king's vault to retrieve the scepter of succession, a magical relic that legends claim to be able to determine who should be the rightful ruler of the kingdom. The king kept his treasures in no ordinary vault, however. The so-called Vault of Rings was designed to not only keep out thieves but to train his heir, who would be unable to access the kingdom's wealth until he or she could overcome the trials and obstacles found within the vault...
This special module marks the fiftieth adventure in the Dungeon Crawl Classics series. The adventure features a unique map composed of concentric rings that rotate as the characters explore the dungeon. The module is printed to include a map on the inside cover that physically rotates, so the DM can follow the dungeon rotation as the players explore!