Promise Paen left the planet of Montana after her father was killed by pirates. She joined the Republic of Aligned Worlds Marines to get away. Years later she is back on Montana as a sergeant of Victor Company. Due to casualties caused by a pirate raid as the Marines landed, Promise is promoted to Lieutenant of the remains of Victor Company. And then the Lusitanian Empire came calling, trying to use guile and force to get the Montanans to switch alignment. Can Promise, Victor Company and the Montanan militia hold out or will all their sacrifices be in vain? A tautly written SF military novel worth reading.