Honourbound is the debut novel by Rachel Harrison. 

This is a story of Astra Militarum Commissar Severina Raine and her regiment, the 11th Antari Rifles. The novel sees the Antari face their arch-enemies, the cult known as The Sighted, in a tense confrontation. But the followers of Chaos know many hidden secrets, some of which may shine a light on Raine’s own past. Can she stay true to her oaths and the Emperor and guide the Antari through the trials that await them