From the blurb:
Sri Aurobindo turns the legend of Savitri into a symbol of the quest of humanity for the crown of immortality. He fills the frame of the legend with a wealth of spiritual and mystic imagery, invests the characters with a profound evolutionary significance and lifts it up into an epic of the Conquest of Death for Man by the Divine Grace.
The Book of Beginnings is a line-by-line commentary on the first Book of Savitri which begins the narrative with the symbol Dawn and the fate of humanity that hangs in the balance before Savitri.
The Yoga of Aswapathy and the secret Knowledge that is revealed to him form the rest of the Book.