A secret society exists who guards the location of the Holy Grail.
Another secret society exists to guard the identity of that secret society.
A key is hidden someplace in Italy that unlocks a box with the identity of the person who knows the leader of a hidden society that maintains a code to a door that leads to a tunnel where a vial holds a small scroll with the correct spelling of Jesus's middle name, which, then spoken into a yet buried well within a dismantled pyramid will activate a machine which will record the voice of the person who has spoken into the well and play it back on speakers connected to a hidden closet in the Vatican, where the Pope keeps his shoes.
P.S. Jesus's Mary used to own a pair of those shoes, but a smaller size, and her shoes still exist and are sometimes worn in public by... ahhhhhhhhhgggggg.