You close the door leading north from the statue room and jam it in place with several crossbow bolts. Then you head south. The corridor turns east then south again, then ends with a door, not locked, leading into a room filled with rubble (mostly pottery). The wall to the west has been torn down to reveal a tunnel leading west, back to the entcance of this underground complex. You return to where another section of the corridor is leading east and follow it there. After about 60 feet, the corridor widens into what appears to have once been a small shrine, for to the northeast, steps lead up to a platform of gray stone. Sitting atop the platform is an ancient altar, little more than a jagged block of black marble with a shallow concavity on top of it. This basin is filled with what appears to be filthy water. From a "safe" 5-feet distance, Adalbert promptly checks it for magic. The altar radiates a faint conjuration aura. There is a pair of closed doors leading south-east.

Spoiler
Show
Adalbert know (arcana): (1d20+7)[19]