Excellent, although very short, story about Corvus Corax and Raven Guard legion waging guerilla warfare behind Horus' lines.

Still recovering from treacherous attack by Alpha Legion, Corax leads his legion (what remained of it in any case) and allied bands of legionnaires against the enslaved and entrenched planetary systems held by the Traitors. Goal is simple, stretch traitors thin and force them to waste manpower on chasing ghosts instead of putting everything towards Terra.

And then, all of a sudden additional Raven Guard units, long time considered lost on battlefields of Istvaan, come in with information on a world held by the Traitors. Their advice is to take the planet because it would be loud signal to all loyalists that Traitors will be harassed wherever they are. But can these newcomers be trusted or is this just another ruse by Alpha Legion?

Action scenes are great, Corax taking down armored vehicles and engaging in combat with Traitor Legionnaires, Raven Guard infiltrators [literally] gliding between enemy fortifications and moving silently to take out guards before taking out strategic positions in order to pave way for armored units, shadows moving in and linking with the resistance - Raven Guard is truly power to behold.

I like Alpha Legion for their approach to unconventional warfare but while legions of Hydra are very brutal and seem sadistic when waging war, Raven Guard are true hit-and-run undercover operatives that still have human streak in them (similar to Salamanders). They do not sacrifice anything in vain. In my opinion they are more than match to Alpha Legion's way of conducting operations.

Highly recommended to all fans of Horus Heresy and Raven Guard in particular. ( )