Volume 2 of The X-Files Mythology collection is the second DVD release containing selected episodes from the third to the fifth seasons of the American science fiction television series The X-Files. The episodes collected in the release form the middle of the series' mythology, and are centered on the discovery of a mind-altering extraterrestrial "black oil".

The third season of the American science fiction television series The X-Files commenced airing on Fox in the United States on September 22, 1995, concluded on the same channel on May 17, 1996, and contained 24 episodes. The season continues to follow the cases of FBI special agents Fox Mulder and Dana Scully, portrayed by David Duchovny and Gillian Anderson respectively, who investigate paranormal or supernatural cases, known as X-Files by the FBI.