The cast for HBO’s House of the Dragon is coming together. Variety reports that Steve Toussaint, Rhys Ifans, Eve Best, and Sonoya Mizuno have joined the Game of Thrones prequel series, which is expected to debut next year. Mizuno, best known for her performances as Oscar Isaac’s dancing parter in Ex Machina and Lily Chan in FX’s Devs, will play a character named Mysaria, who “came to Westeros with nothing, sold more times than she can recall. She could have wilted… but instead she rose to become the most trusted — and most unlikely — ally of Prince Daemon Targaryen, the heir to the throne.” Matt Smith was previously announced to play Prince Daemon.