The Vanishers (or Stinkwort and Buttercups)
Mulder and Scully get called into a kidnapping and one of the suspects is an invisible being. Both agents deal with the concept of true love, but Mulder gets caught indulging his base desires. Scully must make a choice, but can Mulder convince her to make the right one?
Mulder takes his video obsession a bit too far, but at least he solves the case.