(Spoiler alert: Do not read on unless you’ve watched “Black Mirror” through the Season 4 episode “Crocodile.”)

Anyone who knows what “Black Mirror” is will understand this — and if you don’t, you just haven’t been paying enough attention.

The dark technology-obsessed show seems to have just as much fun messing with viewers through its musical selections as any other tricks it employs, but one song in particular has stood out as the “Black Mirror” anthem for many fans: Irma Thomas’ “Anyone Who Knows What Love Is (Will Understand).”

The 1964 track has been featured in several installments in the anthology series, going all the way back to Season 1’s second episode, “Fifteen Million Merits,” starring Jessica Brown Findlay. Findlay belts out the romantic notes on the in-universe competition show “Hot Shot.”

“It was originally selected for [‘Fifteen Million Merits’] because it was, it has the sound of a timeless haunting classic, yet wouldn’t be familiar to most viewers,” creator Charlie Brooker tells TheWrap. “Idea was to have the character of Abi sing a song of earnest beauty.”

The track was used again in Season 2’s “White Christmas,” Season 3’s “Men Against Fire,” and now Season 4’s murder-packed episode “Crocodile.”

Brooker’s co-showrunner Annabel Jones says he “has loved [the song] for a long time” and they keep bringing it back because Brooker “liked the idea of nesting all the episodes together in an artistic universe of sorts.”

“Oh, I think you know it is just — it’s an Easter egg,” Jones tells TheWrap. “I think it’s something we just love and find very emotive. And it’s something that’s really worked for us as a motif. And so if we can bring it back in and it adds to the overall sense of the universe or connection between some of the things that we’re talking about then that’s great. But it is a lovely piece of music.”

That lovely piece of music has accompanied some pretty grim episodes. But hey, it is definitely a bit of continuity fans appreciate each time they hear it — even if it is the prelude to a gruesome death.

See a clip of Findlay singing “Anyone Who Knows What Love Is (Will Understand)” below.

“Black Mirror” Season 4 is available for streaming on Netflix on Dec. 29 at 12 a.m. PT.