Book Seven: The Book of Yoga. Canto 6: Nirvana and the Discovery of the All-Negating Absolute.
Savitri is now living in a blissful inner state, conscious of her soul and by its puissance uplifting everything that surrounds her. This is the first psycho-spiritual transformation that she has undergone. But for her mission more is needed. She must reclaim her universality and transcendence. She must enter the last secret. She must dwell in the supramental world as in her natural home. Not only the soul but also the nature must be free and discover its Godlike stature. The great Shadow, the Inconscient that lies at the back of all things, comes to deviate her from the missioned path. It is the voice of Night that is chased away by the voice of Light. Now she must completely rid herself of every trace of the ego so that the Supermind could find a place in a vast and infinite consciousness. Savitri listens and absorbed in a witness state, enters the sheer stillness and impersonality of the Absolute, the state of Nothingness, the Nirvana that annuls everything. She becomes one with infinity and eternity.
About Savitri | B1C1-10 The Response of Earth (p.5)