Of all the devout warriors in the Adepta Sororitas, none are as renowned or battle-hungry as those of the Order of Our Martyred Lady. Yet while others seek glory in their own martyrdom, Sister Helewise is determined to stay alive so that her death might serve a greater purpose, when the God-Emperor wills it.

Assigned to Fleet Quintus of the Indomitus Crusade, Helewise and her Sisters follow an ancient route of pilgrimage in an effort to rediscover and liberate the shrine world of Cion, once a sacred bastion of their order. In retracing the steps of Saint Katherine herself, their faith will be tested to the extreme as they attempt to uncover what became of their Sisters stationed in the daemon-infested sectors beyond the Cicatrix Maledictum.

As their mission lurches from disaster to disaster and the Emperor's voice grows ever more silent, the Sisters of Battle must trust in bolter, blade and their own unbreakable bonds in order to drive back the darkness of Imperium Nihilus.