The armored skiffs hum low over the gray, humid earth, speeding toward the Castle of Silence. An AI gunship escort follows each skiff, weapons trained on the dark horizon. Inside your skiff's cockpit, the pilot grimly triple-checks the cloaking device to ensure they have enough charge for the ride back. Knight-Brother Mountain unlocks his harness and enters the ship's passenger hold, casting an apprising glare over the lot of you. You may have been hand-picked by Iron King Ischyros himself for this mission – even made to swear an oath of secrecy on pain of death – but the Knight-Brother's judgment was subject to his own insurmountable standards.
"Wake up, soldiers," Knight-Brother Mountain says. "We'll arrive within the hour. Consider it your new home; you're gonna be here a while."
Mountain flicks a button on a terminal in the center of the hold, portraying a holographic projection of a grand ziggurat, countless miles tall and wide, extending far deeper underground: Agatecastle is its official codename, but it is better known now as the Castle of Silence. Once home to millions and millions of souls of every race and walk of life, it is now nothing but a grave.
"For reasons unknown, Agatecastle fell to the Dreaded Ones, millennia ago," Mountain begins. "Either they infiltrated before the Castle's Heart could erect its protective barrier of light, or, worse, they broke through that barrier. If it's the latter, then whatever broke through could still be out there. And they'll come for the other Castles sooner or later. Agatecastle exists on no official records anywhere in any of the nine remaining Castles, so we have little to go on. All we know now is that the place is crawling top to bottom with Dreaded Ones.
"Your primary mission is to discover why the so-called Castle of Silence fell. Data chips, paper records, get whatever you can find that points to something concrete, something we can kill. As for your secondary mission: As you know, every Castle has a self-destruct mechanism, known as the Sword of the Five Gods, located on Layer Zero. It can only be operated by the keys and authorization codes held by the Castle's royal family. These should be located somewhere in the royal Palace, all the way down on Layer One. Find the keys and the codes from Layer One. Infiltrate Layer Zero and arm the Sword of the Five Gods. Then get the hell out of there."
Knight-Brother Mountain looks over his shoulder, through the glass windows of the cockpit, and flicks off the hologram; there is no need for it anymore. The dead steel walls of the Castle of Silence lurk at last upon the horizon.