This is a concise guide (10 or 12 pages) to a 3-act rescue story: Challenges for each act, the types of characters, a guide to the antagonist. While reading it I kept brainstorming twists and events that would make the 2nd act drive the players to their knees in despair, and from there see a chance---just a sliver---that can help them achieve the rescue. This guide won't waste your time or your money.
Starting to plan an adventure from this is the difference between starting with an outline of good questions or starting with a blank page.
I was a little disappointed to see a handful of editing mistakes, and in something of this quality they stand out more than they might in other books. But the tiny errors aren't enough to take off even a half-star in my rating.
[5 of 5 Stars!]