The massive invasion force of Operation Serpent has descended behind enemy lines. Their mission is to obliterate the military power of Clan Smoke Jaguar and seize the homeworld of Huntress. Commanding this historic assault is General Ariana Winston of the elite Eridani Light Horse mercenary brigade. After a year's voyage through deep space, they have arrived.

But the battle has only just begun. The dangers are more far-reaching than Winston ever feared. And the Jaguar garrison is far more cunning than the troops of the Inner Sphere ever believed. For now, emerging from the shadows, a new threat is bearing down on the Serpent armies. The greatest danger to humanity's future is right in their midst. And it is about to ignite the fires of a war to end all wars.