From publisher blurb:
The Scalding Wastes of Kavva’tak lie west of the Valdu’vae Barrier Peaks, an inhospitable stretch of sand and rock. With the day comes the unforgiving sun and the nights the biting cold. One hopes to find respite among the scant refuges offered to a weary traveler crossing these sands. The Oasis of the Swallow in Flight is among the few along the northern passage that provided safe harbor. That was until the scattered reports of the deadly encounters with wild monkey-like beasts. Only the desperate and foolish now dare to add this stop… unless they heard word of what else was discovered, a crystalline treasure found within the rocky embankments.
The Crystal Hearts is a combat encounter, ranging from medium to deadly in difficulty for four to six players, averaging 9th level.