Emma D'Arcy plays Rhaenyra Targaryen in "House of the Dragon."Ollie Upton / HBORhaenyra Targaryen has been gunning for the throne in "House of the Dragon" after her half-brother usurped her.At the end of season two, she hatches a plan that could finally put her on top.Here's how she becomes queen in "Fire and Blood," the book the show is based on.Warning: Major spoilers ahead for "House of the Dragon" season two finale and the book "Fire and Blood."Rhaenyra Targaryen and her biggest rival, Alicent Hightower, form a pact to take over the kingdom in the "House of the Dragon" season two finale.