Firstborns

When Captain Malcom Kin, captain of the West Army, received orders from the master-at-arms to eliminate a people called the Firstborns, who were deemed enemies to their way of life by the Ten heads of state, he immediately began to ask questions about killing unarmed people.
"That is genocide," he whispered.
The master-at-arms promptly reminded him of his duty as a captain in the army. Captain Kin reluctantly accepted his orders. But unknown to him, those orders will take him on a journey to learn the truth about the ten heads of state, as well as himself.