Book of Sorrows: Book 4 of A Dragon's Guide to Destiny

When a series of earthquakes in Tamaras rocks both the ground and an increasingly divided and troubled society, the people blame the earth dragons. Both the government and its opposition, the Austeres, ask Serazina, Heroine of Oasis to intervene. Although she learns that other dragons consider the earth variety to be rude, secretive, and possibly treacherous, her desire to keep the Tamaran chaos from affecting Oasis takes her into danger.

In Tamaras, she, Druid, the Dragon of Destiny, Phileas, Guardian of Oasis, and Tara, a cat who's used up more than a few of her lives, discover a society with undercurrents at least as treacherous as the earth dragons.

Tamarans pursue pleasure in order to escape a mysterious emotional pain whose source is unknown. The Austeres, enemies of self-indulgence, waste, and welfare, say that the people can only become happy when they replace sensuous excess with stripped-down simplicity.

Investigating further, Serazina and her companions discover that the source of Tamaran disruption is a mysterious force called the Book of Sorrows. To learn its secrets, they must go deep into the earth to face both the giant Dragon queen and a race of beings whose name no one dares to speak.