Can anyone help me recall a certain book?

Question

I'm trying to remember a book I read a long time ago, I remember it's in a series.

There's a boy who can travel to different worlds through a warp zone location located in a subway train station on Earth. There are dogs guarding it on Earth as I think I recall it. One of the worlds he travels to has no land, it's all underwater, the people there live in houses they make on giant platforms miles long. The people breathe under water with special goldfish bowl type helmets with little harmonica looking filters. The boy discovers different fruit in that world and finds that the people farm under water.

I canno't recall the name and I've tried searching for it. Can anyone recall this book and/or series?

Answer 1

D. J. MacHale , the Pendragon series.