The actor appeared in the season 6 spacefaring tragedy, “Beyond the Sea.”

Black Mirrordoesnt just traumatize its audience, it also leaves a dark imprint on its stars.

Josh Hartnettis still recovering from the nightmare fuel explored in his one-episode stint onCharlie Brookers sci-fi anthology.

Black Mirror. Josh Hartnett as David in Black Mirror.

Josh Hartnett as David in ‘Black Mirror’.Nick Wall/Netflix

For a married father of four, inhabiting that dark headspace took a toll on Hartnett.

We did that for two nights, and it was really horrible, Hartnett said during aVarietyprofile interview.

It was horrible to imagine because thats the only way I can do it.

Im not much of an actor.

I have to really put myself in a situation.

He added, Thats the job.

Sometimes you have to go to places you dont want to go to.

Im not great at getting out of it, especially if its hard to get into.

They need things, so I cant really bring it out.

Its not an option.

IntrueBlack Mirrorfashion, this is eventually used to horrifying effect.

But before David spiraled down a dark path, Hartnett saw him as a hopeful character.

“And for that sin, Charlie Brooker had to destroy him.”

Colonizing the moon, or even Mars, that sort of thing didn’t seem like a distant possibility.

In our reality, this was the time of the Gemini space program and people going to the moon.

It was all happening!

But this isBlack Mirror, so everything goes very, very pear-shaped after that."