The time after Josh and John left was relatively peaceful. Since they had Henry, he could just talk with the Undead, and in doing so, he learned quite a bit from them. More than just someone called the King of the Undead showed up. He learned about the City of Newborn, which was an Undead City.
He learned that their king was a wonderful person, kind, caring, and always looking out for them. Life there was simple and easy. From the Undead he talked with, they all seemed to enjoy their new life. Henry thought about returning to his friends back in that Jungle City to tell them about Newborn.
Simply because Newborn seemed like a haven for the undead. He wouldn't force them but just tell them about it. Just in case he couldn't, he asked the undead he talked with to pass the message. Saying that there was plenty of undead and bugs in the Jungle City out north from here.
