First is the straightforward summary of the highest story arc.
The second is by asking a question that sums up a main character conflict of the book.
Here's the question I've come up with so far for my current WIP:
What if the only way to save your family's throne was to betray it?
I like it so far. It can be tweaked a couple of different ways but the above pretty much nails the inner conflict of one of my POV characters.