is this adapted from a book?
Yes, a novel called "A Song of Ice and Fire".
Game of Thrones
 It is an adaptation of "A Song of Ice and Fire", George R. R. Martin's series of fantasy novels, the first of which is "A Game of Thrones" (1996). 
when do the dragons appear in game of thrones In the tenth episode "Fire and Blood". what is the storyline of this series? It is roughly based on the storylines of the "A Song of Ice and Fire" book series by George R. R. Martin, set in the fictional Seven Kingdoms of Westeros and the continent of Essos. the episode is a part of which main series? "Game of Thrones"
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Game of Thrones [SEP] Introduction
Game of Thrones is an American fantasy drama television series created by David Benioff and D. B. Weiss for HBO. It is an adaptation of "A Song of Ice and Fire", George R. R. Martin's series of fantasy novels, the first of which is "A Game of Thrones" (1996). The show was both produced and filmed in Belfast and elsewhere in the United Kingdom. Filming locations also included Canada, Croatia, Iceland, Malta, Morocco, and Spain. The series premiered on HBO in the United States on April 17, 2011, and concluded on May 19, 2019, with 73 episodes broadcast over eight seasons.