Well, let's think it through. He has read and loved The Lion, the Witch, and the Wardrobe. When he visits the home of the author, he finds a fancy wardrobe in the author's attic. He approaches it cautiously, opens the door, and is disappointed at what he finds. He was hoping that it was not an ordinary wardrobe. He was hoping that this was the m_______ wardrobe that would lead him to __________.
I don't know if you're expected to draw parallels between Douglas' dashed hopes about the wardrobe with his other dashed hopes that the film touches on, but you probably could.