23th Dearth, 5060
Reaching the ruin, the party found the figure exactly as expected. They followed it underground, to find a thousands-years-old pathway laden with traps. They got through most of them, but triggered some summoning and force wall effects (force walls blocked their retreat). They found signs of diminishing but continuous habitation, and walls of graffiti scraped away and written again hundreds of times (mostly ornate paeans to a blood-drenched dominatrix goddess named Nouliss-Hakkari). Running low on energy, they stopped to meditate to replenish some of their depleted energy.
Continuing deeper into the desert ruins, the party fought some planar creatures in a room with summoning circles. As soon as they defeated the creatures (who were called, not summoned), they noticed a half-dozen vampires lounging in the next room, enjoying the battle from the other side of a portcullis. After a few minutes of banter, they closed in for the kill.
It was a rough fight, but the party defeated the vampires and their minions (destroying one vampire and petrifying another) before sealing off the hallway and retreating to a more defensible position to rest and recharge.