So when laurie_robey's sorceress Mirima headed off alone to the keep, Miha changed to her human/spider hybrid form and attacked. Mirima was only slightly wounded (but it became important later) and started blasting the aranea spy, so Miha quickly fled up the side of a nearby building and used an invisibility spell to escape.
Alerted by the spells some blocks away, the rest of the party rushed to Mirima's defense, but by the time they got there it was over and Miha was gone. (hantamouse: "I knew it! I knew it!") Shortly thereafter, the horde began their two-pronged attack. Thanks to jamesbarrett's spotting of hidden siege engines, most of the town's soldiery were sent to the north gates to reinforce the bridges across the river — unfortunately, that left a severely weakened force guarding the west wall, where a squad of hill giants were sent to breach the wall with thrown rocks. (hantamouse again: "They are the siege engines!") The party went out to deal with four of the giants, while a detachment of Lions of Brindol were sent to deal with the other four. After a short but vigorous battle (which included Balgor having to make the first save against death from massive damage that's come up in our ~10 years of D&D 3.x), the heroes were victorious, but the Lions were not so fortunate, being slain to a man after only taking out two of the giants, and the wall was breached.
The party performed a quick retrograde maneuver (also known as "Retreeeeat!"), intending to get into position to reinforce the wall as countless hobgoblins swarmed towards the breach — at which point the red dragon Abithriax came flying over the city, blasting buildings and soldiers right and left with his fiery breath. Abithriax concentrated on the southern part of town, to draw defenders away from the battles to the north and west. The party, being the only ones likely to be able to do anything about him, chased him to the southern part of the city and engaged him in battle at the south gate — where it really got ugly.
Abithriax perched on the roof of a building by the gate; Mirima used dimension door to take herself and Balgor (who already had a notch for one dragon on his belt) up to the roof, which would have been a good strategy, except that the second part of Abithriax's mission, aside from burning down as much of the town as possible, was specifically to take out Mirima and Brother Michael (sirfox's gnoll cleric of Lathander), and Mirima basically handed herself to him on a platter.
To make a long story short, one round later, Mirima was on the ground two stories below, quite dead. The annoying part of it, from laurie_robey's point of view, was that if she hadn't been down the few hit points from Miha's attack earlier in the evening, she would have survived. She'd have been unconscious and at negative hit points, but that could be easily remedied by application of a cleric or even a heal potion. Instead, the dragon's attack took her to -11 hit points, killing her outright.
The battle deteriorated further from there — Balgor couldn't manage to land more than an occasional blow on the dragon, whereas everyone else's attacks were just plain bouncing off (Abithriax has a sick AC, and even sicker attack bonuses). Brother Michael went down to a claw followed up by 8d10 flame breath (the flame breath also instantly killing Captain Sorannah, an old friend of the party's from very early in the game) — but luck was with sirfox, as Brother Michael stablized at -9 hit points. Dreklin (hantamouse's rogue/ranger archer) shoved a cure moderate wounds potion down the gnoll's throat as the dragon gloated a bit, then flew off, blasting more buildings.
The party got the last laugh, however, as Balgor used the magic staff they'd claimed from Ulwai Stormbringer to cast control weather and call down a rainstorm that quenched the fires. The party rushed the bodies of Mirima and Captain Sorannah to the Cathedral of Pelor, where judicious use of diplomacy convinced the high priestess to use her only true resurrection on Mirima, figuring that Brother Michael could cast raise dead on Captain Sorannah in the morning, assuming they all lived that long.
We ended the session there, with the party panting for breath in the Cathedral while the battle rages on outside. Who knows what horrors the rest of the night will unleash on the already battered and weary party? Have they seen the last of Miha? Of Abirthriax? Hopefully we'll find out next week!