Ever look at a photo of Scooby-Doo and the Mystery Inc. gang and feel like there’s just something missing? Not Scrappy-Doo, the Mystery Machine, Gigi Hadid, or even the gay icon that is Hot Dog Water, but someone else entirely?

If so, you’re not alone … and may be experiencing what some on social media have dubbed a reverse Mandela effect.

While this theory first emerged from the depths of Tumblr back in 2019, per Know Your Meme  — “every time I look at the mystery gang I have this like visceral feeling that someone is missing but nobody ever is,” wrote technogodhead before joking that the alleged character was “banished from this timeline and our collective memory as a species” — this mystery re-emerged on TikTok last month thanks to culture influencer @jpall20.

“My brain is broken and now I’m nauseous,” she began her now-viral video uploaded on January 23. Though @jpall20 was not initially sold on the iconic Tumblr post — “I was like ‘I love Scooby-Doo, these are the only characters,” she recalled — a quick glance at a drawing of the gang made her question everything.

“I looked at this picture and I got this sinking, nauseating feeling that something’s wrong,” she continued, taking care to note that “the power of suggestion” could have played a role in her visceral reaction.

But even with this caveat — and another citing commenters’ arguments that maybe the Mystery Machine’s absence or even side characters like Scrappy-Doo could be responsible for this strange collective feeling — she stood by her gut reaction.

@jpall20 Idk this really has me messed up lmao #scoobydoo #mysteryinc #cartoons #mandelaeffect #nausea #mandela #powerofsuggestion #mysterymachine ♬ Blade Runner 2049 - Synthwave Goose

“Maybe it’s because there’s only five of them so it’s like, not an even number,” she added. “Why does everybody have a pair except for Velma?”

While the answer to @jpall20’s question may only remain between them and God, several offered their theories for this strange phenomenon.

“The hidden 6th member is probably just ur brain remembering that they usually have help from someone attached to the plot of the episode,” wrote @izuagbe, while @randym444 cited Scooby-Doo’s status as an anthropomorphic dog as the reason behind this confusion.

“I think it’s because Scooby feels like a person while you’re watching. But looking at a photo you only see 4 people when it feels like you should see,” they explained.

@abdelrapon, however, decided to get a bit meta with it, arguing that we, the viewers, were the sixth members of Mystery Inc. all along.

“You watched it so often as a child and you was feeling like you [were] part of the group so YOU are the missing one” they added.

But regardless of what’s behind this anti-Mandela effect, we can only hope we’ll pull the mask off of this caper, so to speak — after all, it’s the only mystery that Mystery Inc. can’t solve.