The crews work to contain a dangerous forest fire and save a group of environmentalists protesting a housing development.
Mulder and Scully track a legendary creature that has roamed the New Jersey countryside for over forty years.
In Summer 1999, Megan wants to be adventurous and makes fake IDs for the gang. In Winter 1999, a burst pipe leads the Landrys and Isabella to a messy night at the Chambers house. Isabella wants to help but is met with resistance from Megan.
Mulder and Scully are stalked by a deadly new life form that has invaded the bodies of a volcanic research team.
When Dr. Fredrick Walden (recurring guest star Rob LaBelle), the famed linguist who was injured while studying the caves, awakens suddenly from a coma, he possesses fantastic powers and goes on a dangerous mission. Meanwhile, Lana helps Clark celebrate his "birthday" in a very special way. Lex and Helen endure doubts and stress while planning their wedding. And Lionel forges a surprising alliance with Chloe.
