If you complete the The Imprisoned Elf quest, it will reveal a potential escape method.You can get an update to this quest by activating the Withermoore's Soul Jar quest.You'll gain another bit upon entering Fort Joy's ghetto region.You can gain an optional entry by having an elf eat Atusa's leg and gaining her memories of someone named Verdas.Tell her you were sent to help and she will ask about Atusa, saying that she was going to help them escape.
