The X-Files, season 8

John Doggett is assigned to find Mulder and does not believe any of it. That is the year's engine: a competent, literal man working a case whose file is full of things he refuses to accept, partnered with a woman who used to be him. He is not a fool and the show does not treat him as one, which is what makes the arrangement work.

The search runs cold until a field in Montana produces bodies, and one of them is Mulder's. He is buried. Months later a man walks out of a hospital who was in the ground, and the mechanism that brought him back is the same one that has been converting people quietly for some time. The thing being grown inside them is not a hybrid in the old sense. It is a replacement, and it is durable in ways that make the old programme look like a rehearsal.

Alongside that: Scully's pregnancy, and the question of where it came from. There was an attempt years ago, with material taken from her, and the records of it are not where they should be. Whether the child is the product of that or of something else is asked repeatedly and answered evasively.

The season ends in a room in rural Georgia with everyone who wants the baby converging on it, and the replacements standing down at the moment they should be closing in. William is born. Nobody in the room understands why they were allowed to leave.