A new Astra Militarum novel by Russell Zimmerman launches in paperback.

 Auxilia finds the young and brash Castellan-Colonel Roane forced to take charge of a ragtag auxilia built around a clan of despised abhumans, overseen and openly loathed by a murderous commissar and consistently ignored by the Departmento Munitorum. Roane struggles with the impossible task of hammering his unit into Cadian shape, while those around him would rather see it destroyed.