Sefi the Quiet is an Obsidian, the sister of Ragnar Volarus and the daughter of Alia Snowsparrow. Sefi earned her nickname after she took a vow of silence when her brother, Ragnar, was sold into slavery.
In Morning Star, Sefi witnessed the death of her brother Ragnar on her home planet, and is convinced by Darrow to join his cause in freeing the lower Colors from slavery. She kills her mother to usurp the position as the Queen of the Valkyrie, after her mother refused to ally with Darrow in freeing the Obsidians.
Her tribe caused a great disturbance on Darrow's starship by attacking other highColors, both allied and captured, after being shown the HoloDisplay of The Jackal executing Narol. The riot is only dissipated after Sevro au Barca willingly offers his and Cassius' lives to them as a peace offering.