Tonight's fight involved a vampire harpy (now named Svetlana, at Lori's excellent suggestion), two advanced mummies, and two advanced plague blights (plus a pit trap filled with brown mold). I managed to do a bit of spooky description by describing the mummies and plague blights as spooky dancers, wearing porcelain masks and flirting indecently with each others' bandages. And the harpy provided the music...
It turned out that the big advantage of the undead in this fight was that they all had powers that could shut down the party members for a few rounds. The vampire harpy had her captivating song, the mummies had their despair ability, and the plague blights had their gangrenous stench. (The gangrenous stench was horribly poorly described; it wasn't clear whether it was a free action or a standard action, and it wasn't clear what the duration was. I ruled that it was a standard action for 1d4+1 rounds, since that was the typical duration of other nausea-causing spells.)
On the other hand, the PCs had the big advantages of a friendly ghost (who was immune to all those effects), flight to get them out of range of most of the attacks, and a summoned fire elemental.
The harpy's music actually captivated Larissa and Kyle, which was not the result I was expecting. (I was expecting to get Turok, but he rolled a 20.)
So Turok went headlong after her, trying to kill her to free Kyle and Larissa.
It couldn't resist Turok's sword effectively, so it dove for the covered pit in the floor. This brought Kyle, Larissa, and Turok down to the level of the other undead, who could use their own abilities. The pit locked shut, and it got a bit of security--except from the ghost, and when it readied an action to attack the ghost, it had to break off its song.
There followed a fight around the pit, with Kyle being particularly hurt because he was consistently on the ground. He managed to get affected by both the mummy rot from the mummies and the gangrenous touch from the plague blights. (Another question: for monsters who are advanced enough to have the save DCs of their disease attacks increased, such as advanced mummies, does that increase the DC of the later saves? I ruled that it didn't, which meant that Kyle made two successful saves and took no damage from the plague blights' disease.)
Another weirdness: it turned out that fire elementals are not immune to disease, so the fire elemental spent a few rounds retching from nausea. This was a little odd for all of us to imagine.
Shortly after the harpy's song ended, the mummies used their despair ability, which froze Kyle and Liandra--and Kyle was above the pit. So after being attacked and fireballed a bit, one of the mummies calmly stepped onto the trapdoor with Kyle, dropping both of them down into the pit of brown mold. But even though he was nauseated, Turok managed to interpose himself to prevent the trap door from closing, enabling the others to maintain access. After the active combatants and the fire elemental destroyed the undead at ground level, Liandra flew down to harry the mummy with her flame blade (very effectively, particularly since it was vulnerable to fire), and Larissa added magic missiles, destroying it just after Kyle went unconscious from the brown mold.
I managed a few good bits of description, particularly the description of the undeads' entrance, and the final just-about-to-die moment of the mummy reaching out to Liandra for a kiss.
Final results: the mummies and plague blights are dead, but not the vampire harpy. Kyle and Turok both infected with mummy rot (Turok did great on Will saves tonight, but lousy on Fort saves), Turok down 8 points of Str damage--and the PCs are trying to keep going. It's an exciting time.
I'm not quite sure why I'm feeling so pleased about it, but I'm not going to quibble with myself. I do feel tired, but I feel tired and satisfied, not exhausted and disappointed the way I often do. May it be always so.