Eddie and Susannah, having been brought through their doors from New York City, are learning from Roland how to be a Gunslinger. He is apparently a very good teacher because both Eddie and Susannah are able to prove their worth and dexterity very early on. Roland, on the other hand, is slowly falling apart mentally. We know from the first book that Jake met up with Roland and traveled with him to see the Man in Black. But Jake died, sacrificed by Roland for the Dark Tower ("Go then, there are other worlds than this"). Roland remembers all of this happening, yet, it didn't happen, because Roland killed the man who initially killed Jake. This is all very complicated but you'll get it. He is living in double memories and it's driving him mad. Unfortunately, Jake Chambers is in NYC and living in his own hell because he knows he's supposed to be dead in "real life" and he's supposed to meet Roland and die again. But he goes on living, trying to understand what's happening to him.
Eventually, through a horrifying process, Jake makes it to Mid-World and back to Roland and the others. Their minds clear and they continue the journey to the Dark Tower. Almost 600 pages of adventures also give us Oy, a billy-bumbler, who befriends Jake and, oh my goodness, I want an Oy of my very own. Alas.....
We're left with Blaine the Mono. Blaine is a pain. And Blaine ends this novel by taking our friends on a riddle-filled, suicide trip at 800 miles per hour.
I've summarized this greatly because well, you need to read it. This is a fantastic adventure. I started reading it on a plane to NYC (coincidence? I think not!) and was just pulled right back in. Fantastic.
Also, Stephen King actually published Charlie the Choo-Choo. It arrived yesterday at my home and it's just as creepy and awesome as you think it would be (you have to read Wastelands to understand this!!!)