Alys Rivers (Gayle Rankin), the woods witch of Harrenhal, is much, much older than we thought. Gayle Rankin as Alys Rivers in House of the Dragon season 3 episode 7. Ewan Mitchell as Aemond Targaryen and Gayle Rankin as Alys Rivers in House of the Dragon season 3 episode 7. Gayle Rankin (Alys Rivers) in House of the Dragon season 3. This backstory for Alys Rivers is never revealed in George R.R.