The X-Files, season 5

He is not dead. What he is, briefly, is convinced — that the work was a fabrication run on him for years, that the men he trusted were assigned, that his sister's abduction was a story told to keep him useful. Scully's cancer goes into remission because a chip is put back in her neck, which is either a cure or a leash and the season never resolves which. The man who assigned her to Mulder in the first place turns out to have been reporting to the other side the whole time.

Then a harder thing. A girl in a care home has Scully's genetics and no explanation, and by the time Scully understands what she is looking at — a child made from material taken during those missing weeks — the child is already dying. Nothing about it is undone.

The other half of the year turns outward. A group of people gather at a bridge expecting something, and something arrives and burns them. It happens again elsewhere. The men who have been running the programme are being hunted by a faction that does not want the plan to proceed, and the faction has no faces.

By the finale there is a boy who can read minds and is worth more to everyone than he should be, an assassin firing through a window, and a fire that takes the basement office and every file in it. What Mulder and Scully know at this point exists only in their heads.