First in the Thorn's Chronicle Adventure Path
From the introduction:
Another girl gone missing!
Three in one month from Threshold alone, with more reports of abductions coming from the outlying farmsteads, and as far away as Eltan’s Spring and Verge.
Vampires, some say. Goblins, say others. Yet there is no sign of forced entry, no signs of struggle: just an open window and an empty bed.
For 4th - 6th level characters.