I found the answer, a secret passage! We pulled on a torch sconce and a section of the wall opened up to reveal a dark corridor.
(Divination +10)
The corridor took us to a well-lit chamber. I saw the markings on the walls and floor; someone had been doing some very powerful magic. I immediately suspected Necromancy, someone trying to raise the dead. The focus of the power led me to the center of the designs, where the mummified remains of a halfling lay. He was still dead, but I wasn't sure for how much longer. Suddenly, five other halflings burst into the crypt! They were wearing priestly gowns and held long, sharp knives.