Certainty's Quest: Legend of the King's Die

One day, Certainty's best friend Probs asks Certainty to help him look for an old treasure that existed in his family. Certainty, of course, decides to help his friend, but can't help but wonder if there's more to the story than what his friend told him. Should they even be looking for the treasure at all? Why was it locked away in this dungeon?  Why does Probs want this? 

All we know is that the treasure is called the King's Die and the adventure that awaits them will be a grand one!