The Roman Cult of Mithras

I found the image of the bust of Mithras, ca 200AD and the hand in the same book, but they were not linked in any way. I pasted the bust and the hand down (on an image of the Carlsbad Caverns in New Mexico) and then cut up letters to serve as asemic writing. I was going to make up a story about a "secret handshake and password" to enter the caves where the followers met. AND THEN I GOOGLED Mithras and discovered this! (I swear I did not know what the initiates called themselves--please read.)

From Wikipedia:

Mithraism, also known as the Mithraic mysteries, was a mystery religion centered around the god Mithras that was practiced in the Roman Empire from about the 1st to the 4th century CE. The religion was inspired by Persian worship of the god Mithra (proto-Indo-Iranian Mitra), though the Greek Mithras was linked to a new and distinctive imagery, and the level of continuity between Persian and Greco-Roman practice is debated. The mysteries were popular in the Roman Military.

Worshippers of Mithras had a complex system of seven grades of initiation and communal ritual meals. Initiates called themselves syndexioi, those “united by the handshake”. They met in underground temples, called Mithraea, which survive in large numbers. The cult appears to have had its centre in Rome.