B.P.R.D. The Devil You Know revolves around the immediate aftermath of the apocalypse caused by the familiar Lovecraftian monsters. Luckily, they were stopped by the B.P.R.D., but unfortunately there is still much work to be done and the fiery Liz Sherman must help the Bureau in helping survivors left in the rubble. However, B.P.R.D. The Devil You Know #2 takes place immediately after these events with a strange cult that has developed because of the end times. This cult subsequently is left with idle hands and while the B.P.R.D. is busy at work, the cult is busy causing more chaos in the shadows.
B.P.R.D. The Devil You Know #2 is an entertaining comic book, but is different than typical B.P.R.D. works in that it is focused on universe building and side characters rather than relying heavily on Hellboy. Usually I do not like universe building for the sake of it, but B.P.R.D. The Devil You Know #2 does a wonderful job in giving you another perspective of the Mignolaverse.
Overall, if you are a Hellboy fan, delve into this comic and enjoy the universe. I highly recommend it. However, unlike some comics where you can enter in halfway and get the picture, you must read B.P.R.D. The Devil You Know #1 because B.P.R.D. The Devil You Know #2 will not make a whole lot of sense otherwise.
B.P.R.D. The Devil You Know #2 is now available from Dark Horse Comics.