Door in the Wall (by Marguerite de Angeli)?

We just started independently reading this book in class. We read up to page 25. I am a really slow reader and I olny got up to page 15 in the time we had and I had absolutely no idea what was going on in the story since I was rushing. For homework, I have to write a 1 1/2 page "free-write" on what I read up to page 25. Can someone please tell me what went on ? thanks