Helix has just graduated from the Academy. He is top of his class and seems to have a great career ahead of him. But when he is sent on his first mission, he finds that the enemy has been warned of his task. Arriving at the base, he is immediately surrounded and captured. To the Academy, the failure of a first mission marks a failing career ahead. Almost no one is retrieved from failing missions. A year later, the Academy suffers heavy attacks and sends Adenine to rescue her brother, Helix. Returning, they and other agents help turn the tide of the battle and force the enemy to retreat. But the attack leaves the Academy weak, the enemy relentlessly preparing for the next attack.