A startling blue light is the last thing a few select humans see before awakening in a military barracks with a uniformed hard case, one of their own, breathing down their necks. From him they learn that extraterrestrial aliens have blue-lighted - that is kidnapped - them and impressed them into a mercenary military corps. They must learn to pilot some huge war machines called All-Terrain Leg-Driven Weapons Platforms - ATLs for short - or work as menial slaves under the lash of brutal alien masters. Going along to get along, the captives train to fight for their captors, but never miss an opportunity to learn about their strange environment and the odd beings who control them. They have no idea where they are - or even when - but escape is never far from their minds. And under duress some humans can be very persistent.