Book Seven: The Book of Yoga. Canto 7: The Discovery of the Cosmic Spirit and the Cosmic Consciousness.
Realisation of the impersonal Brahman is not enough for the transformation and the complete conquest over death and fate that Savitri seeks. It sets the soul entirely free and if it wills the soul can through this state merge into the Nirvana of the Beyond and be done with birth and death and care. But Savitri goes beyond to reach to the still greater transcendence, the Supreme One who is there behind life and nature and each and every element. Savitri now enters that cosmic Being and the Transcendent Supreme who alone has the Power to redeem this fallen life. Having arrived at the state of Nothingness she becomes everything. Thus equipped she is now armed with the knowledge and the power to face the forces of fixed fate and take on the challenge of inconscient death that pulls down everything back into the abyss.
About Savitri | B1C3-11 Towards Unity with God (pp.31-33)