Why use such a seemingly out-dated method of smuggling code? Because nobody has the technology to deal with it, for one thing. Only someone like Jay is equipped to develop the daguerreotypes and find the hidden messages. And he's the only one with the key to the otherwise unbreakable code. No wonder everybody's after him. It's a relentless pursuit, and you begin to wonder if sleep-deprived Jay will collapse before he can figure things out.
You can learn a lot about photography from Paris City of Night, and there's local color galore to go along with all the action. Check it out.