Henry has lost his parents, so he has gone to live with his uncle. Henry's uncle owns a huge house, and every room is different, with anything you can imagine. Henry's Uncle does not allow him to go into one room though, so Henry tries to find a way to see what is inside.
Henry makes a plan with his friend Toby. While Toby distracts Henry's uncle, Henry goes to find out what is in the room, but finds only a box. When he opens it, he finds another, and another, and another, until he can barely open the next box. Then, there is a flash of light, and Henry is gone. His uncle finds out, and goes into the light after him, along with Toby.
Henry and his uncle fight, but move past it. They meet Jessie, who will help them along the way, and they also find people only known as minions. The minions try to stop Henry, but he doesn't know why. He then finds out who controls the minions and his plan, and he sets out with his uncle and Jessie to defeat Lucas.
Henry finds Lucas and fights him. He learns what he did and why, and finds out that Toby was working with Lucas. He defeats Lucas, and (SPOILER!!!!) frees his parents .
Henry nd his uncle find the box, and they return to the mansion. They then lock the box away so that nobody will find it. They then have an argument about Henry opening the box, but his uncle lets him off with a warning.
Henry decides to stay with his uncle for a while, but he can't help wonder what other mysteries there are. Henry also had collected some items from his adventure. Jessie had also come with them, and Henry's uncle allowed her to live with him in the mansion.