In the next chamber, the kobolds have a trap for you. While the slingers, dragon shields, and the wyrmpriest stay out of the way on top of platforms, a huge boulder is released into the room. It is designed to roll around the room and crush anyone who tries to pass through the room or attack the wyrmpriest.
Dr. Carion saves the day by pulling all the kobolds down into the path of the boulder.
You use the room where the slingers were hiding to take an extended rest.
Level 3 Orb of Inevitable Continuance (PHB p. 238) — Amon
Encounter XP = 850 (170 ea.)