Medusanna

A priestess of terrifying power convinces the Se’sehen a yuan-ti tribe from the distant jungles of Chult to serve her growing cult of Sseth. The merciless god of the serpent people who languishes in the foul plane of Smaragh. Where a trapped and desperate Karell can only hope Arvin will find her before the House of Serpents finally destroys their last hope for freedom.

From the Paperback edition.