X marks the spot

Just when Song Hei thinks that things have finally
begun settling down, Jinqiong, her half-sister, now
apparently a wanted convict, turns up at her front door
with Kim Jongdae in tow. She claims to have stolen a
jewel that has, firstly, set the remaining four families
after her. Secondly, there's someone else chasing her
down for it: someone much more dangerous than the
former, someone who also wants the jewel for its ability
to break any curse and won't stop until he's gotten the
jewel andtaken both Jinqiong and Jongdae's lives.

There's a couple of problems: Jinqiong can't get rid of
the jewel without using it or being killed (and she has
the annoying habit of drinking her problems away every
time she encounters one, which is frequent), she's
holding Kim Jongdae as ransom for their help (and he
has something he wants himself from the jewel), the
man after them is basically unstoppable, half-monster
and they don't stand much of a chance against him if
they can't figure out how to use the jewel against him.

With no other choice, Baekhyun reassembles the crew
and they head towards Hell's Gate again, hoping to both
rid Jinqiong of the jewel and, at the same time, free
Taeyong from his eleven hundred year old curse for his
help.