The second volume in the X-Files Mythology series focuses on the Black Oil aspect of the series. Compiling 15 episodes from seasons 3 to 5, this volume is mainly features episodes about the parasitic, black colored oil like alien substance that can infect humans. The episodes included here: Nisei, 731, Piper Maru, Apocrypha, Talitha Cumi, Herrenvolk, Tunguska, Terma, Memento Mori, Tempus Fugit, Max, Zero-Sum, Gethsemane, Redux, and Redux II, are all excellent and just about classic X-Files episodes that are compiled here for a cheap price, which is what makes the X-Files Mythology series worth owning for casual X-Files fans who don't want to shell out the money for complete season sets. If you are a die hard X-phille, you're better off with the season sets which include all the great stand alone episodes (where as the Mythology sets revolve around the series' single storyarc), but other than that, this is a solid deal for casual X-fans.