All pre-written adventures should be written like this. This book is a wonderful example of what adventure supplements can be, and it's wonderful!
The Civil War supplement for Marvel Heroic Roleplaying followed the Civil War story in the Marvel comics. I'm not a Marvel Comics fan (as in, I don't read the comics) and, if you're not either, that shouldn't deter you from picking up this book.
This Premium version of the Civil War also contains the Operations Manual. Since I have the Basic Game and have read that quite a bit, I didn't do a complete read-through of the OM as included in this book. I did skim the pages and it seems to be the exact same book, although, according to a couple forum posts I've read, there were some very minor changes to some areas of the text to clarify some of the confusing things that came to light after the Basic Game was released.
The Civil War Event consists of three different Acts. The Acts take your group through the period just before the law, as the law passes, and the aftermath of the law. There's so much wonderful goodness contained in the book! I'll try and tell you what's in there without giving anything away.
In this Event, the US Government, and other governments around the world, start out debating a law that requires superhumans to register with their government. Superheroes are going to have an opinion of this, whether they're for it, against it, or just don't care either way. The wonderful thing about the way this Event is written is that, not everyone has to be on the same side! At the beginning, this will likely cause some strife between the characters, but it probably won't come to blows.
Then, during Act II, the heroes must pick a side, because if they don't, the powers that be will interpret their non-choice as a choice. Again, this section has lots of notes on how to play the Event from either side; whether you're running from the law, or chasing down the rebels.
Act III is the culmination of the Event and has got so much explosive awesomeness that I can't even pick an item to talk about!
The Event also includes lots of new Datafiles for popular heroes. I really liked seeing the Punisher and Deadpool in there.
The part that gets me so excited about this Event is the discussion on how each side would view and react in each scene described. It's a list of possibilities and I can see story threads stretching out to an infinite horizon. There's so much to do, so many possibilities and this is an excellent launchpad for any Marvel story.
[5 of 5 Stars!]