This is a short entry to the Sacrifices Arc that explains where on earth James Potter has been and what he has been doing.
It's a lot darker than it probably sounds.
The whole idea of the magical maze is a fascinating one, and one that I'm quite intrigued by. Watching James face things he would really rather not was rough, even for someone who does not have a whole lot of sympathy for him at this point.
There's not much more to say about a short story in the middle of a series that is not full of spoilers except to suggest that if you have been reading the rest of the series, this is definitely a useful viewpoint to add to it and might help you understand things better.