The Luna He Betrayed Is the Hidden Commander (S1)

The story

Alpha warrior Elowen buried her military record to become Gareth's peaceful Luna. He returns from war with a celebrated new bride and expects Elowen to heal his pack, raise the other woman's pups, and still bear his heir. Instead, Elowen severs their mate bond, reclaims her fallen family's house, and follows evidence of a massacre back to the battlefield—where her hidden command may be the kingdom's only defense.