Ghost Black - Daughter of Mars, #3

Everything Risa Black believes is a lie. Her angel is dead, the cause she's killed for is as false as her metal eyes, and the one man she thought she could trust has deceived her for sixteen years. Smothered by deepening layers of conspiracy, she decides to embark upon the most frightening mission of her life: leaving the Martian Liberation Front. After eight years of trying to free Mars with high explosives, and a reputation as a less-than-sane killer who hears the voices of angels in her head, Risa didn't expect to walk away clean.
Her former bosses won't let go easy, agents on both sides of the war want her dead, and truth is in short supply. A politically connected enemy threatens to purge the Front of those unwilling to play by their rules. To survive, Risa must become that which she has so long denied being-an assassin. With bombs poised to bury her former life and everyone associated with it deep beneath the surface of Mars, Risa has thirty minutes to make an impossible choice: save the life of her daughter by killing her best friend, or disarm the bombs and let her child die.