and his sidekicks (called ka-tet) were minding their own business and kept going towards the Dark Tower when suddenly they had to interrupt their journey in a hurry, find some shelter and stay put for several days. Roland tells a story from his younger days to kill time (Skin Man). In that story he in turn had to kill some time and recounted another - this time fictional - story named The Wind Through the Keyhole. Confused yet? I hope the following picture helps.
So there is a story inside of a story inside of a story. The outer story takes place shortly after the events of Wizard and Glass. Despite King's reassurance in the Foreword it does contain some spoilers, albeit minor ones. It does not move the overall plot even by an inch. To cut to the chase, this part closely resembles the predecessor book I mentioned so if you like it you will like this story as well. As a corollary it follows that you can read this book at any time after book 4
The middle story called Skin Man was the most interesting one. I was excited about it when I learned it was about Roland's days in Gilead shortly after the events of his flashback in Wizard and Glass. I hoped to see more Alain and Cuthbert, but got Jamie instead - and let us face it: Jamie is a pale shadow of these two. Other than this the tale was exciting and quite gruesome.
The inner story which gave the title to the whole book began slow and was quite boring and predictable for approximately one third of it. I can even give the exact place where it began to become interesting: with the appearance of the Tax Collector.
At this point I have to confess I hate the end of the whole series with a passion. I will not discuss it here, but I actually like this book. Yes, it does feel like King has some unused scenes from both last Roland's ka-tet travel (outer story), his flashback of book 4 (middle story), and an unrelated story loosely connected to mid-world (inner story), but it kinda sorta works - in a good way.
My final rating is 3.5 stars
rounded up. Why up? Because with the exception I mentioned above I was never bored with the read. I might feel 4 stars is a little bit high rating, but 3 stars are most definitely low.
P.S. Clint Eastwood in his prime would be THE actor to play Roland; nobody comes anywhere close - see the first picture as a proof.