The 2011 re-read:
Roland and his ka-tet of gunslingers ride into Calla Bryn Sturgis, a town with a problem. Once every generation, a gang of marauders called The Wolves ride out of Thunderclap and steal half of the town's children. The ones that return come back roont, or brain-damaged. Can Roland and the others stop the Wolves before Susan gives birth to the demon in her womb?
It was a long wait between Wizard and Glass and Wolves of the Calla. Was it worth it? Well, does a horse piss where it pleases?
The main story of Wolves of the Calla is right out of The Magnificent Seven or Seven Samurai. The gunslingers ride into town, prepare the town, and settle the bad guys' hash. The secondary stories, of which there are several, are what make the book. You've got Father Callahan from Jake, Eddie, and Susannah's world and his fearsome burden, Black Thirteen. You've got someone in town helping the Wolves. You've got Roland and his arthritis. You've got Calvin Tower and the vacant lot containing the Rose. And most of all, you have Susannah's disturbing pregnancy.
The gang going todash was one of the more interesting parts of the book and something I'd forgotten about in the years since I read this book the first time. I devoured the book in a day and a half when it first came out so I must not have savored it. There were so many wrinkles to the story that I'd forgotten.
I love how the Man in Black doubled back and met Callahan at the Way Station while Roland and Jake were on in trail in The Gunslinger. In the revised edition of The Gunslinger, Roland contemplates putting his quest on hold for a few years and training Jake so he'd have another Gunslinger with him. Would they have met Callahan if they'd let the Man in Black get away? Tantalizing...
People say that the long flashback in Wizard and Glass fleshed out Roland's personality. I'd say watching Roland interact with the people of Calla Bryn Sturgis in this book went a lot farther in showing what kind of man Roland was before the world moved on.
I can't really say much more for fear of giving too many things away to people who have never read it. If you like the Dark Tower, this one is probably in the top three books of the series.