From Fallen London Wiki

Action purge is not allowed on comment pages.

It's not locked, per se. This quality is given if you hit Wounds or Nightmares 8 at Hallow's Throat. That way, you get a cider option (or the ones by naturally hitting Wounds or Nightmares 9) that returns you to Hallows Throat, rather than your Lodgings. Otherwise, it's mechanically the exact same with Fall as without.