In the far reaches of Imperial space, a ferocious warp storm approaches an Administratum world, cutting off the entire planet from the rest of the Imperium. As their towering grey spires are punished by endless rain, countless administrators, tithe-masters, and book-keepers are forced to evacuate. Among them is Greta, a lowly data-drone with a terrible secret, wanted for questioning by the sadistic Imperial interrogator Stefan Crucius. As disaster strikes and the pair are left stranded in the depths of the drowning city, captor and captive must cooperate.

In the midst of a vast gas nebula lies a remote watch-station, hanging silently against a tapestry of dying stars. It sits alone, patiently awaiting lost travellers adrift in the freezing vastness of the void. To such souls it appears as a blessing, a safe haven from the warp storms that wrack the immaterium and destroy the ships of those foolish enough to test the tides. To Captain Arq and her crew, it is one thing - refuge. But things are never so simple.

For Ianthe, war is all too familiar. A former soldier in the Astra Militarum, she now serves Inquisitor Covenant as an agent of the Throne. Her first mission sees her investigating a cult called the Children of Eternity. Falling foul of the local Enforcers, Ianthe soon learns that war in the shadows is seldom straightforward and that the local, angry law-keepers are the least of her troubles.

Belisarius Cawl, Archmagos Dominus of the Adeptus Mechanicus, is the most brilliant mind alive. For 10,000 years he has furthered the cause of mankind, working under the aegis of the Emperor and Lord Commander Roboute Guilliman to prevent the inexorable march of the alien and the traitor. Many call him heretic, but all must recognise the magnitude of his achievements, for who else but he was entrusted to create a new generation of Space Marines?

As an agent of the Throne, former soldier Ianthe serves Inquisitor Covenant and faces some of the most dangerous and insidious threats the galaxy has to offer. On the hunt for the rogue psyker Silas Norn, Ianthe and her associates run afoul of the Imperial authorities and are imprisoned. Norn too is captured and incarcerated, but with the ability to manipulate the minds of his victims he is far from easy quarry. To stop him, Ianthe must not only find him; she must overcome the buried ghosts of her hidden past.