Energizing into a metal-walled room the party sees...
"The room is dusty with no marks on the floor and appears to be disused, other than the crystals being placed on the pad. Each of the 6 pads has a 1’ dimly glowing purple crystal on it in a silver stand or socket of some kind. Fine silver wires run from each of these crystals back and forth across the pad area. Several of them run up the wall to another silver socket that is empty."
They also see 3 floating brain-creatures using their tentacles to manipulate the purple crystals and silver wire. The creatures drop what they are doing and rush the heroes, who respond with steel and spell.
Uthal and Kordan score telling hits on one brain then with a FOOSH the Wizard unloads a fire shroud into the room roasting all three. A short time into the fight Kordan finds himself grappled by one of the brain creatures and repeatedly bitten, all while inside his head the Spirit of Arnd shouts at him Go! Hit it back! You can do this! Eventually Kordan breaks free but it is an unpleasant experience at best. In a long and harrowing fight the party wins out but is battered and bloodied by the end, standing over the shattered brain creatures and leaning on their weapons to catch their breath.
Recovered they notice that one door in particular shows signs of activity.
"The door is closed and locked and shows signs of claw marks and bloody smears on the outside. Behind the desk is a headless body slumped back in a chair. On the desk before him is a glowing purple crystal similar to the ones outside. A small boxlike object lays on the floor near the chair."
Uthal is instantly fascinated by this boxlike object and begins playing with it. Despite the obvious - perhaps even desperate - crying out to fate for something bad to happen the Goliath remains undisintigrated and happily puts the shiny away in his pack for future investigation. The party notes that the colorful clothing on the headless corpse looks similar to the tattered remains seen on the creatures encountered below.
Moving to the last set of doors (which appear to be larger than the rest) the party decides to actually listen before entering. They are are rewarded with a set of screams from the other side of the door followed by a swish as they slide into the walls. Inside is a scene of horror:
"There are 5 chairs around the room placed in front of tables. Sitting in those chairs are what look to be uniformed humans. The top of their heads is open (their heads appear to have exploded), blood streams down their bodies and is splattered over nearby consoles and floor, and what appear to be their brains are crawling away from their bodies."
The brains have sprouted legs and antennae. The blood is fresh and the fight is on. The horrifying things scuttle to advantageous positions (they are brains after all), their antennae twitch, and mental attacks slam into our heroes. The warlock and the wizard flame the room, the fighter and the barbarian stab the survivors and the bard trades mental barbs with the last survivor. Then the suicidal brain-thing takes a flying leap at Uthal and pays the price as it is swatted out of the air by his great black spear, violently and thoroughly ending its brief existence.
The party surveys the room and realizes they will find no answers here. They have come to destroy the Pool of Twilight and it is clearly not in this room. Returning to the anteroom outside they begin to puzzle out the crystals, the wire, and the glass disks and realize that their answer is likely found somewhere else, somewhere they can only reach via this alien device...