An official The Last of Us poster teased the game's sequel back in September, fans have now realised.
It depicts someone (we presumed Ellie) holding a switchblade knife. Fern branches are wrapped around her arm, while moths perch on her and nearby.
Naughty Dog's reveal trailer for The Last of Us: Part 2 revealed an older Ellie - now the game's main character - with a new tattoo on her arm.
That tattoo? It's of a fern branch and a moth perching on the end.
The developer last night revealed the tattoo design in full for fans to incorporate into cosplay, which is when the penny dropped.
Tong's poster was actually more for The Last of Us: Part 2 rather than the original.
You can no longer buy the poster, which was sold by Mondo on his store only in limited numbers. We're sure its price on eBay just shot up higher.
While we're on the subject of hidden secrets, The Last of Us fans have a huge theory about Joel in the upcoming game.