Black Mirror season 4 has been described as “darker” than its original series and has seen a raft of twists and turns.

But it’s not just the dark mood of the first season that’s been tweaked, with its cast of characters including a woman who has lost her husband, an astronaut and a zombie, and a character who has been diagnosed with schizophrenia.

“It’s a really dark season,” showrunner Charlie Brooker said at a press conference on Wednesday.

“There’s definitely a little bit of a darker tone to it than what we initially intended.

It’s also a season that I think will be the last season of Black Mirror.”

Black Mirror season 3 saw Brooker take a much darker tone, but it wasn’t quite as bleak as this one.

“It’s definitely darker, I think,” Brooker added.

“You’ll find yourself watching this season more through a dark, creepy lens.”

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Black Mirror is one of the UK’s most popular science fiction and horror series, with a fanbase of around 70 million fans.

The latest season has been released in the US on Netflix.