Okay- not the best thing I've ever read, but it was pretty d@mn good. It was a nail biting, on the edge of your seat, "gasp- oh no he just DIDN'T" kind of manga. Perfect 9. The art was great, story was great, the characters were well developed. If I could change one thing about this manga, I would want to make it longer, but a mangaka knows better than anyone what they want to do with their story so, kudos to Haibara.
I'm not going to give any spoilers; mostly, I couldn't believe someone hadn't already written a review for this masterpiece. Give it a try- hope you like it. :)