The galaxy is burning. The Emperor’s loyal primarchs prepare to do battle with Warmaster Horus and his turncoat Legions on the black sand of Isstvan. Such dark times herald new and yet more terrible things still to come, and when Astropath Kai Zulane unwittingly learns a secret that threatens to tip the balance of the war, he is forced to flee for his life. Alongside a mysterious band of renegades, he plunges into the deadly underworld of Terra itself, hunted like a criminal by those he once trusted. In the face of betrayal, Kai must decide where his own loyalties lie and whether some truths should be buried forever.

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Space Marines from the Traitor Legions on the run on Terra itself. If that's not enough, then how about one of the greatest secrets of the 31st millennium being revealed: just what did happen to the Thunder Warriors?

The eBook edition includes integrated illustrations of characters and events from the story, and an afterword that places the story in context within the series.