Presented as the history of the progenitors of the human race and the truth regarding the underlying spiritual dynamics of the gods that spawned us - as produced through automatic writing and drawing during a six month period in 1925 (why not published until 1956 I am unsure). The text is "inspirationally dictated" through "El Eros", otherwise known as H.C.Randall-Stevens).

The style is a quaint mix of olde worlde thees and thys with frequent Kiplingesque beseaching to "my beloved children" with equally frequent promises to be brief - taking up quite some time.
Nevertheless the first part is a readable cosmic history of the pre-human celestial shenanigans that saw the creation of the uber-gods and their subsequent off-shoots - including the narrator, Osiris himself, and the ultimate creation of the human expressions of, variously, Adamic rescuers and the rest (victims of satan's wily plots and plans) - but who knows whom is who? The history involves the familiar destrucyions of Lemuria and Atlantis and the subsequent development of the race via Egyptian culture etc

The second part, while promising an elucidation of the lost eleven principles of Osiric teaching is a slightly disappointing series of childlike automatic drawings illustrating cosmic, moral and spiritual teachings.

(In my copy there is also an intriguing jump in chapter numbers from XI to XXIV between the two parts)

The only othe review I have seen is pretty scathing, but if you're reading this type of literature, an open mind is helpful and while not particularly inspiring, the book did stimulate thought and reflection.