SPOILERS!
So if I interpreted it correctly, the Kid is the miacarried baby in universe A and was intended to be the original Henry, therefore he should not be there as he is already dead in this universe. And in universe B he has a successful life because the mother left Matthew, unlike in universe A, which may have been because of the loss that they shared with the miscarriage. While in universe A, Henry pushed his father off the ledge because he intended to kill Ms. Deaver for infidelity, right after he pushed him off the ledge he crossed over into universe B where Matthew B locks him in a cage because "he's the devil" for telling him he's his son and knowing everything, but Ms. Deaver took his son when she left (the Kid). The Kid finds him 27 years later after Matthew B dies still in the cage and still a boy. He's set free and sent to a hospital where he kills some people for getting too close. There Molly senses he doesn't belong and her and the Kid help to get him back to his own universe, which he returns to 11 days after he's gone missing but doesn't remember anything, while trying to help Henry, the Kid gets stuck in universe A where Warden Lacey locks him up because "HE'S the devil". He has to wait 27 yrs to be freed but once he's freed anyone who comes into contact with him dies and Henry is reluctant to help him get back. Instead he locks him up again. Even though he KNOWS who the Kid is. It's totally messed up. The Kid was never a monster until THEY turned him into a monster by locking him up and taking away his life, then he had a chance to return home but HENRY WOULDN'T RETURN THE FAVOR?!? Then locks him away again!?! So who's the real monster?! I'm clearly upset by this.. And so is the Kid because his sinister smile the day before christmas says Henry's f*ckd. From what I can tell the next chapter is going to be about the Shining and I think this story is over