Very nice episode with some fun stuff, like code on newspaper, random World War II soldier, conversation with a coma victim, "ghost" telling Pierce to not listen to another "ghost", etc. This might also be the first episode where we could relate deeply with Pierce's paranoia toward corporations (if you have the nerve to mess with honest farmers, then you deserve something nasty like sarin in your face).
If there was any weak spot, it could be Lewicki's strike, since it didn't seem to be important at all. Everything else was above average.
This is unbelievably smart show and it is not something you get very often on a TV. It's a great mix of crime, drama, humour and knowledge. This episode was in particulary great and it could easily be a full-time movie played in the cinema.