Anna Milton was a fallen angel who became the human daughter of Richard and Amy Milton by removing her grace. Due to her newly reawakened ability to hear angels speaking, she was pursued by demons and angels alike. Sam and Dean protected her until she managed to regain her grace and fend off her pursuers herself, even briefly becoming lovers with Dean. Due to Castiel's betrayal, the Host of Heaven eventually captured Anna and took her back to Heaven. She returned to Earth in "The Song Remains the Same" with the intent to prevent The Apocalypse from having occurred by killing John and Mary Winchester to retroactively erase Sam and Dean Winchester from existence. She was killed by Michael to protect the Winchesters.