Travelling aboard a warship of the Black Templars, Sister Agentha of the Adepta Sororitas Orders Dialogus finds that her skill with languages is required when the vessel intercepts an ancient message, potentially dating back to the dawn of the Imperium – and containing the voice of the Emperor Himself. But with vicious aeldari raiders closing in, can Agentha complete her task in time? And will the Black Templars even want to hear the voice of their god?