Three replacement characters were created at the start of session 10. Wolfe (elf), Samantha aka Sister Sam (cleric), and Anton (specialist).
The party decided to do some exploring and make their way again to Thistleblack. Along the way a Satyr in a magical grove offered up wine and food, and conversation. The party was suspicious, and declined the offer. A sleep spell later and all except Mira lay unconscious and the Satyr again offered wine and food. Mira, concerned for every one's safety, accepted. After some time passed the Satyr departed and the party awakened to continue their journey.
As a boon the Satyr had granted a Mira a minor one-time bonus in combat.
Returning to Thistleblack they continued exploring the under-city. Entering previously bypassed areas they located a shaft leading down to where they expected to find another way into the crypt with the well armed and armored zombie had been standing guard. Indeed, at the bottom of the shaft was a secret door to the expected location. Having been noticed by a zombie guardian, the door was quickly closed and the shaft ascended.
As the group was about to continue exploring the upper level a stone on stone grinding noise heralded the arrival, through the stone wall of a bizarre being with a skin of stone, three arms, three legs, and a mouth on the top of its head. In simple common tongue it requested precious metals. Uncertain of the risks involved in refusing the demand, the party gave up a quantity of copper and silver which the entity promptly devoured.
As a reward for their generosity, the creature answered questions about the existence and location of the sought after library.
Back above ground they encountered a pteranadon and some giant ticks. The battles were difficult and very nearly cost the lives of two members of the adventuring band.
Eventually, after resting and licking their wounds, they opened a deep shaft hidden in a ruined tower and descended to the library entrance.