Tamsin Blackwood, the current Dragon Keeper of House Blackwood, upholds an ancient pact: her family guards the Black Dragon and its Hoard in Blackwater Lake, and the dragon protects Blackwater Hollow from the Rourke Crew. She even sold her mother's jewelry to fund her husband Gideon's surgery. But when Gideon and Blythe discover gold beneath the lake, Blythe convinces everyone the dragon is a hoax and Tamsin hoards the gold. Gideon betrays her, and the townsfolk plunder the lake until the real Black Dragon rises—yet they still refuse to stop. Blythe poisons the dragon through Tamsin's own hands and reveals her affair with Gideon. Tamsin flees with the dying dragon; in Clearwater they are saved, and a mysterious White Dragon brings Silverroot to cure it. Both dragons become her allies. Rourke's crew then seizes Blackwater, forcing Tamsin to return. The two dragons crush them together. Blythe frames the dragons at the Mountain Council, but Tamsin arrives on dragonback and exposes every lie. Blackwater finally renounces the Hoard; Gideon confesses the truth and begs forgiveness. Tamsin accepts their apologies but does not return—she rides off with both dragons to Clearwater, choosing a life that truly respects her.
