Lazarus 

This provides the usual X atmosphere plus a few standard TV thrills. Not a favorite with the fans it seems, but I think it is as deep as X-Files has been.

Which is to say, it is not mind-bending stuff because we have a 'real' super-reality but within those limits, it exemplifies some worthwhile layering much better than usual for the series. Usually, what extralogical forces Mulder and Scully encounter can be understood as inner mental urges of the characters, standard noir rules; Mulder's fear of a fiery love affair from his past as the volatile combustions of Fire, Scully's assertion of feminine independence in Jersey Devil and so on.

The story here is that simultaneously two men die, FBI agent and psychopathic robber, one is resuscitated back to life but in those few minutes of dead time the identities have shifted, the 'evil' consciousness returning in the agent's body.

The robber (as the agent) seeks to be reunited with his girlfriend accomplice, with whom they had a deep, dangerous love affair, this is mirrored in the past love affair Scully had with the colleague she resuscitated. So her ex- is now 'evil' and acting strange, which from Scully's always hesitant pov becomes the reluctance for commitment we know from Jersey Devil.

In the latter stages, we have Scully 'trapped' between the passionate couple, seeing as helpless observer the kind of corrosive passion she has kept from herself, conjuring in the man's mind memories of a past trip together as her attempt to awaken the 'good' person she knew.

Even more tantalizing: in this quasi-magical reality of having survived death, the robber experiences a nightmare of betrayal and heartbreak, with love as a sham.

So this is an attractive episode in narrative terms, again constrained by hard presentation. It is deep, in the sense that you can read a series of altered realities as inter-leavened dreams from opposing pairs of eyes.