The Defiant Agents (Ross Murdock Series, No 3)

Synopsis - Ancestral memory – Travis Fox, once the unwilling captive of the runaway spaceship Galactic Derelict, has volunteered – eagerly this time – for the mission to colonize Topaz. But when he and his fellow Apaches find themselves reverting to the ways of their ancient warrior race just as the expedition from Russia has been transformed into a Mongol Horde encamped across the mountains, it becomes clear that more than their own lives is at stake...