I ran into an old Dutch translation of this little book. I have known about it for a long time, did not buy it when I was studying Mithraism, but I was still curious enough to read it years later. Mead opens with ‘an alternative’ history of Mithraism. Alternative to the scholarly version of Cumont. Mead has not only used archeological sources, but also early written sources and this sheds a nice light on the subject. The booklet is actually a translation of what Dieterich has called the “Mithraic lithurgy”, a short text from the “Papyri Graecae Magicae” (see here and here. Mead’s translation is alright, his explanation is also alright, but not too interesting. He sees the text as Yogo and comes with a too Theosophical explanation of initiation and mysteries. Not a boring read, some interpretations give something to think about, but not a booklet that I would advice if you want to learn something about Mithraism (save for the first part to offer an alternative history).
More about Mithraism on Gangleri.nl you can find by “browsing” for book reviews and I have some articles on the subject in the articles section.