As with all of the Trail of Cthulhu scenarios I've purchased, Castle Bravo is top notch. I'll give you fair warning. I ran this as a one-shot and it ran 4.5 hours with some serious cuts in material. If you want to include all/most of the hooks and plot lines available in this book, plan it for a 2 session game at least.
Overall, this is written very clearly and is well structured. The book starts out with the standard GUMSHOE story summary and plot skeleton. It then goes into the particulars of the scenario starting with the characters standing on the deck of an aircraft carrier before a nuclear bomb is tested on a nearby item. That's when very strange happenings begin.
The group I ran this for really enjoyed it. It is definitely a "slow burn" where the creepy stuff escalates slowly and then eventually comes to a head. That's when all heck breaks loose and the players have to do whatever they can to survive.
The best part of the book is that it is modular in some respects so that you can easily move the story along if things begin to drag. It is also simple to improvise as your players go off the beaten path. As a GM who routinely runs things fast and loose, I appreciate that.
Overall, this is a great change of pace for Cthulhu fans who are used to classic 1930's scenarios or modern day adaptations. The 1950's McCarthy-esque paranoia and nuclear horror atmosphere lends itself very well to a Cthulhu game and offers something different for your players. For the price, this is well worth your money and then some. Buy this now and run it as soon as you get a chance.
[5 of 5 Stars!]