The heroes (minus a dwarven cleric, who'd simply gone insane in the presence of the leader of the diabolic horde) left the crew to repair the spelljammer while they descended into the depths of the temple. The scale was immense, and the path very long,with nothing but anatomically-worrysome statues to look at on the way.
Mrs Reed passed the time with inane chit-chat, pausing only to look inside a large rock that she mentioned was 'full of gadgets'. The rest of the party didn't waste any time doing the same, being more drawn by the regular booming sound echoing down the corridors toward them.
Eventually, a large(r) room was discovered, where robed cultists were chanting at the behest of a floating eyeball cluster, sending dark motes of energy up into a blue sphere at the ceiling, the impacts causing the noise.
Determined to claim the moon for the Empire of Nerath and get some quiet rest, the team rushed to battle. While its minions fell in short order, the beholder proved more troublesome, killing Dais the fighter with its death-ray and bringing the others to the brink themselves. Neither the ranger eventually shot it as it fled, but the reason for its panic was more alarming, as it seemed the whole place was collapsing.
Reed ran back to the 'rock' full of gizmos, and Neither joined her as she launched what turned out to be another spelljammer. As they sped away (abandoning the drow member of the party) they realised that the valley they had been in was only part of a larger message, spelled out in some ancient tongue on the blue surface of the moon. Then the satellite exploded.
The two of them made it home, and translations from the imperial artificers decoded the message they had read: the moon had been a ward, protecting the world from some unearthly force, presumably now free...
This was the story that a drunken halfling was telling The Red Order, anyway, trying to explain the name of Fallcrest's Blue Moon tavern. They just drank up and headed off to the Silver Unicorn instead.