written by Todd McCaffrey and Anne McCaffrey
published in 2006 by Del Rey Books
novel no. 21 in the Dragonriders of Pern series
novel
Pellar's story provides background information related to the previous title Dragon's Kin. Cristov's story is mostly new material (blue firestone that survives in water) and takes place after the events in Pellar's. The focus of Cristov's story is the problem-laden transition from firestone to the phosphine-bearing rock that is used by later generations of dragons.