You invite a handful of friends round, and then rather casually spill bat's blood into the bowl between the idol's outstretched fore-limbs. There are gasps of delighted shock. You casually spin a tale about finding the thing in a Third City temple, about the curse you have to placate, about the book you expect to publish on the subject. Your stock rises accordingly.

Three nights running, you dream of a limestone cave half-lit by candles. The candles are extinguished, one by one. As the darkness draws closer, you raise your hands to your face and pop it free, easily and painlessly, as if it were a mask adhering under light suction. The cool cavern air on your face-beneath-a-face is delicious. It makes you grin toothily in expectation.

[Note - If you have access to the University, you can research the idol there.]