At this early hour many were sleeping but Defense Complex Tetra II was still up and running at full alert. Those on shift were ever diligent in their duties. Augur sweeps were constant and guards were manning defense positions. With the prior attack on Tannacus, and now a war on Yuion the forces here were not taking any chances in their duties to the Imperium. Mechanicum  and PDF forces on Dependence were mustering to support those fights and tensions were high with the thought of another looming war.     

The Eldar knew that to get into a prolonged war here was suicide against the heavy defences at the complex and took every measure to ensure a quick victory for a timely withdrawl. They attacked just before dawn using the early hour and remaining darkness to allow for deadly alpha strike against the massive war engines and standing indomitable over the complex. This is why their darker cousins were required; shadow rays blasted worth nullifying void shields so lance weaponary could be used to fell the massive walkers.

Dark crystals appeared floating in the air behind defense bunkers and fortified positions that rent wholes in reality and sinister warriors emerged slaughtering the defenders inside. Wave serpents and raiders swooped over the high walls and disgourged warriors into the midst of the complex. The initial assault was total carnage as the defenders found themselves pressed from all sides before a solid defense could be fortified.

A few solid defenses did form around the center of the complex as a few inspiring leaders rallied against the slaughter. However, this didnt last long as the few crippled war engines went critical from their wounds disintegrating areas of defense for the enemy, and with the Imperial Titans gone, the Eldar Titans took to the field intent on cracking open the last remaining bunker to get their prize.

The attack didnt last more than an hour all of the defenders of Tetra II were dead or too wounded to fight anymore. Farseer Ullsandir walked with Illithrys down into the complex to take the weapon that they came here for. Automated defenses awoke to eliminate the intruders, but they were no match for the Farseer as lighting arced from his fingers and struck the machines causing them to overload.

Finally they stood before the entance to the vault. Illithrys used a fusion gun to burn access into the inner room. There in the center of the room stood the stasis cell that held the weapon they needed, but it was empty.

In the corner of the room a dark form melded into the shadows.