Season 9 of the supernatural series begins with the fallout from heaven's angels descending to earth. Sam (Jared Padalecki) and Dean (Jensen Ackles) suddenly find themselves living in a world that is now inhabited by thousands of powerful, angelic beings, some of whom want them dead. The brothers then embark on a journey to reopen the gates of heaven. Meanwhile, Castiel (Misha Collins) struggles to survive without his powers and embarks on living as a human; Crowley (Mark Sheppard), the King of Hell, is kidnapped by Dean in order to find demons on earth; and Abaddon (Alaina Huffman), the Knight of Hell, reappears with plans to take over hell once and for all.