In the year 2063, the final frontier is a battle field. An earth united in peace takes its first steps toward interplanetary colonization, only to be threatened by an enigmatic alien race. Enter the 58th Squadron, a group of wet-behind-the-ears pilots with the Marine Corps Air and Space Cavalry. Under the rigorous tutelage of Sgt. Maj. Frank Bougus, reluctant leader Nathan West and fellow cadets Shane Vansen and Cooper Hawkes embark on a mission to save the galaxy.

When the USS Saratoga passes close to the planet, Vesta Colony, where the Earth colonist were attacked, West goes AWOL and flies down to the planet in hopes that his girlfriend, Kylen, somehow survived.

Nightmares come to life for Shane when a sentry-duty assignment on an asteroid leads the 58th into a bloody confrontation with a battalion of rogue androids, among which are the AI's who murdered her parents.

When mutiny erupts aboard a civilian cargo ship carrying 200 In Vitro embryos, Cooper faces a difficult decision-should he protect his fellow soldiers, or join forces with the rebellious Tanks?

The Saratoga has a mysterious new passenger: a battle-scarred special-forces commando whose classified mission directives put the 58th at his disposal, even if it means leading them to certain disaster.

The Saratoga becomes a pressure cooker of violence and political intrigue when an assassination on Earth forces a delegation of UN officials to use the craft as the site of an important conference.

The soldiers of the 58th become their own worst enemies when a routine supply mission goes awry, leaving them stranded in alien territory and suffering from the effects of a mysterious Chig weapon.

A commandeered alien battleship provides the 58th with information about an important Chig outpost, giving the Earth forces an opportunity to make a Trojan-horse attack against the enemy-if the 58th can learn to fly the craft in time.

After narrowly escaping the crippled alien battleship, the 58th finds itself imprisoned in the catacombs of a Chig penal colony. While Wang suffers in an alien torture chamber, Nathan encounters someone he'd only dreamed of seeing again.

A failed rescue mission leaves the 58th presumed dead, except for Nathan, who lands in the hospital, where a nagging memory that his comrades are still alive is passed off as a result of suffering from severe head trauma.

Christmas Eve finds the 58th in dire straits: its transport vehicle, damaged in battle, is hurtling uncontrolled into enemy territory and the pilots must struggle to stay alive with no power, no weapons, and no hope of being rescued.

Stranded and practically defenseless on an alien world, Hawkes accepts an assassination assignment that's supposed to buy him an immediate Honorable Discharge from the Marines.

The 58th enters the tunnels to try to find and destroy a Chig ammo dump. In the tunnels on the way to the ammo dump, Lubin is killed, and Damphousse predicts that one more of them will die.

Shane risks her life when she volunteers to fight an enemy spacecraft with another squadron, led by a former boyfriend whose new love was killed during a mission.

McQueen seeks reinstatement of his pilot status so he can fly what could be a suicide mission: find and destroy a seemingly invincible Chig super-bomber.

West discovers that his brother has enlisted in the Corps and is serving under a young, gung-ho lieutenant who's so determined to make a name for himself as a soldier, that he will risk endangering the lives of his entire battalion.

The members of the 58th receive letters from home, some with good news, some with bad, while McQueen and Cooper are ordered to cooperate in a TV documentary about In Vitroes serving in the United States Marine Corps.

The exhausted Wild Cards are granted R&R aboard the Bacchus, a pleasure ship where it's said anything can, and does, happen.

A mysterious group of extremely high-ranking officers disembark on the Saratoga and the 58th are ordered to escort an unresponsive space APC. The mysterious APC suddenly locks on their Hammerheads and opens fire.

When Commodore Ross sees there's an opportunity to launch a potentially crippling offensive against the Chigs. Forced to abandon the 58th on a barren planet, Ross leaves the marines to fend for themselves with little ammo, no food-and no hope of rescue.

The 58th is deployed to a seemingly barren moon to make final preparations for a major offensive by the Earth forces, but when they arrive they discover that the moon is home to an unknown species-and that Operation: Roundhammer may cause its extinction.

Tras la aparición de la nave enemiga en el Saratoga y su intento de presentar una propuesta de paz todos los humanos en contacto con esta intentona de parar la guerra se siente estupefactos pero se inician las negociaciones de paz.

El coronel T.C. McQueen comenta con el 58 que parece demostrado que el enviado está legitimado para establecer conversaciones por lo que el siguiente paso es que cada facción establezca los preceptos mínimos necesarios para poder hablar. Los humanos quieren entre otras cosas la lista de los prisioneros de las colonias arrasadas y en esas listas puede estar el nombre de Kylen Celina a la que Nathan echa tanto de menos. Para Cooper el final de la guerra significaría la conmutación de su pena y sería libre. El 58 aún no sabe que el Chig embajador es igualito al extraterrestre que encontraron en la luna.

Los Chigs piden para comenzar a negociar que el jefe ejecutivo de AeroTek, E. Allan Wayne (Richard Fancy), asista a la negociación Los humanos solicitan a los prisioneros de las colonias a lo que los extraterrestres acceden y aseguran que cuando las conversaciones se inicien serán llevados al Saratoga. En la lista de los colonos supervivientes que les han entregado figura Kylen para regocijo de Nathan y sus compañeros.

Cuando McQueen acude a charlar con su escuadrón y estos le solicitan alguna información del enemigo se dan cuenta que se trata del mismo ser al que para evitar su exterminio, creyendo que era el último de una nueva especie, le habían comentado la existencia de la Operación Martillo. Todos se dan cuenta que el enemigo conoce sus planes de guerra y ese puede ser el verdadero motivo de su aparición en el Saratoga con una propuesta de paz.