These undercover operations can be very surprising and reveal a whole new layer to the world and even the neighborhood you are living in. It's a long read. It's not a Robert Langdon thriller but being a real story has its own hook. You could also try Gangland Undercover which is a fact based series aired on History channel.
It's better than watching your average documentary and the production is well done. Not a masterpiece. But it keep you interested.
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