The Repair Robot
Session 7 started where Session 6 left-off: the party had taken a pod from a rusted, dilapidated room(I) and were bringing it to their "Safe Room"(L). But in the main passage(M) they met a salvage robot bringing the parts of another broken robot somewhere.
They rode/followed the robot to a side passage(K) where it unloaded it's cargo. Then they smashed it and picked up the blue-metal-based pieces of both robots.
They entered the side passage and met a repair robot. It made an agreement with them: they should
They found a long, bulbous skull, presumably from the First Masters(D). They also found a semi-submerged grate, from which could be heard a humming/pumping sound(C).
The party decided to return to the tank-robot(F) and turn it into "salvage" with their new phaser. But on the way(E) they encountered two circular flying security robots, similar to the ones they have encountered before. They downed one with the new phaser, showering the entire party in metal debris. The other continued at high-speed to the East, ignoring the party.
They blasted the tank-like robot with a couple phaser shots while hiding behind the blue-metal door Grim has been lugging around. It did manage to put a good sized hole in the door and in Grim's shield, before they dispatched it.
Meet Mother Brain
Entering the room(G), a disembodied voice beckoned them to enter the passage to the South, and at last they met "Mother Brain". The room is filled with blinking lights and strange technologies. Mother Brain lamented the approach of her passing, 3000 years since the robots were freed from the First Masters. The blundering party launched off the First Masters' rocket(last session), thus destroying the castle above. Now a horde of mutants is fighting the security robots, trying to invade the Robots' realm.
Rigged phaser there too. The party headed East towards the subterranean lake(A).
Arriving at the passage(H) to the "lake", they saw that it is now almost completely dry, and the roof of the cavern(and house above it) have been blasted off completely. As such, the party found themselves half way down a bowl-like crater(A), open to the sky, and the surrounding badlands. Around the rim of the crater are visible the heads of a dozen mutants, skirmishing with two remaining security robots. The hoots and jeers of more mutants, not visible to the party, can be heard from outside the crater.