For two years, the developers at Naughty Dog managed to successful keep one of the biggest secrets in gaming. So how is it that they almost spoiled their own surprise in front of millions of gamers? Ah, that's a good story. (No spoilers, I promise!) What happened? "We screwed up," Naughty Dog's Neil Druckmann recently told me, now that he's able to laugh about it. Druckmann is the creative director of The Last of Us, a post-disaster survival-action game that his studio was making in secret since 2009 all the way until December 11, 2011 when it was announced during the Spike Video Game Awards. This was a game from one of the most respected video game studios on Earth, a game that dozens of people were working on, a game that somehow didn't leak to Kotaku or any other outlet. Except that it almost did and, if it happened, it would have been Naughty Dog's fault. That's the short version. The long version, about how Naughty Dog put a Last of Us easter egg in Uncharted 3, thought The Last of Us would be announced before Uncharted 3 came out and then... forgot that the easter egg was in there!... can now be told. Let's go back to 2011. Let's go back to Naughty Dog's big November release of that year and take a look at this little easter egg that was posted online on December 8: Seems subtle enough, right? Someone found a newspaper in Uncharted 3 that mentioned a fungus. Viral advertising for a mystery game called The Last of Us had been making the rounds. It seemed to involve a killer fungus. A connection! And a complication: Naughty Dog, though, was obviously a studio that only made one game at a time. Couldn't be them, right? Here's IGN's Greg Miller back then, trying to work the same rumor and thinking the same things the rest of us were: Got all that? Then get this exchange I had with Druckmann and The Last of Us game director Bruce Straley a couple of weeks ago. Now it can be told! Kotaku: Can I ask—given all the secrecy behind this game—are you able to tell me the story about how it is that the easter egg or teaser for this game got put in Uncharted 3? What's the origin of that? Neil Druckmann, creative director: [laughs] Originally we were going to announce The Last of Us at E3 of that year [so June, 2011] and then we ended up... Kotaku: The year of the [December 2011] VGA trailer announcement... Druckmann: Yeah. So we said, 'Okay, it would be cool. The game will be announced and then Uncharted 3 will come out afterwards. So the designer [of the November 2011-scheduled Uncharted 3] came up to us and said, 'Do you mind if I put in this Easter Egg? So after somebody played Uncharted 3, they'll be like, oh, they're talking about The Last of Us.' 'Cool.' And then we ended up pushing when we announced it and forgot about the newspaper. We just completely forgot about it. Kotaku: When did you remember you had it in there? Druckmann: [laughs] When it was found. When it was discovered, a week before the VGAs. Bruce Straley, game director: [laughs] When it was online. Druckmann: We were in a meeting and we get a text from one of the designers saying, 'Cat's out of the bag.' We were like, what f...? We've held it this long! Druckmann: I'm like, 'Oh no, we've been found out.' Straley: We didn't know. What does 'cat's out of the bag' mean? We get over there and there's just this energy. Druckmann: We walk back to the design pod, and the designer who put it in comes up to me and he's like, 'I just want you to know, you approved it! You approved it.' And I'm like, 'Approved what?' And then we went on NeoGAF or something and someone's like, 'There's the newspaper there.' I'm like, 'Oh no, we've been found out.' And then the awesome things is... we don't know how it happened, but everyone was like, 'It can't be Naughty Dog, because they just shipped Uncharted 3.' Straley: 'They only have one team.' Druckmann: 'They've got to be doing a favor for someone. It's Sony Santa Monica!' Straley: 'It's Guerilla Games. It's got to be Guerilla Games!' Kotaku: It's the new Killzone! Straley: One guy posted something like, 'No guys, I think it's Naughty Dog. For real!' And everyone else is like... Druckmann: 'Don't be an idiot! They're a one-game studio.' Kotaku: Was that you? Was that you in there posing? Straley: I don't have an account. Yeah, that was luck. Kotaku: You had approved the easter egg? When the designer showed it to you, did that come flooding back to you? Druckmann: Yeah. We forgot about it. We should have taken it out. We screwed up. Straley: These games are so big, right? They're several hours long. Every single pixel has to be touched. Every animation is created from hand. It's overwhelming. You can't look over every detail. So this one little thing in the background, nobody's thinking about that. Well, that's one that they wouldn't have been able to blame on us. The game was subsequently announced on December 11, shocking plenty of people. And we'll finally all be able to play the game on PS3 on June 14. To contact the author of this post, write to stephentotilo@kotaku.com or find him on Twitter @stephentotilo.