Escape From Khosht

From the introduction:

The Eye of the Beast - a cut, polished diamond the size of a hill giant’s fist - has been the centerpiece at the Museum of Sages in Khosht for the past decade, where it’s nestled within the eye socket of a cyclopean statue.

It’s worth 200,000 gold pieces.

You now cradle the huge, glittering gem in your arms! It’s the dead of night, and you’re inside the museum looking up through a debarred skylight where a rope dangles, hanging limply at your side. Next to you stands one of your colleagues, a statuesque, swarthy-skinned beauty from Gull named Chi-Chi. Through the hole, on top of the roof, stands your other confederate, a small, quick man named Radnoff.