First there was On the Count of Three, which introduced the fundamental notion of triples. There was actually a prequel of sorts years before — very appropriately a trifecta challenge — about the actual Count of Three and his rabbit fur cloak).
Then came the sequel, Three-peat, which explored the world of triples in more detail. That world spans the gamut from witches to transistors to music theory. (Triples cover a lot of ground!)
Now, at last, the exciting final post of the trilogy! Will the three heroes finally find the three keys, defeat the three dragons, and save the Three Kingdoms?