The new world is BROKEN.
Nothing in Ruby's life has ever been black and white. Even after successfully accomplishing her mission to save Wesley, the danger isn't past, and neither are the difficult decisions.
Solomon demands Ruby's return, but the Marked kids need her to stay with them. Their lives might even depend on it. Wesley begs her not to go, but it's not easy to ignore Solomon. Sam didn't come with them when they left the island, and ignoring a dictator's orders always leads to repercussions.
Doing what Wesley asks might make things worse for everyone. No matter what she decides, some people will die. Ruby must decide who she loves the most, and what she's willing to sacrifice to keep them safe.