The big tip-off for The Last of Us, which gamers found in Naughty Dog's Uncharted 3: Drake's Deception, was completely accidental.
The Easter egg was a newspaper with the headline "Scientists are still struggling to understand deadly fungus."
The Last of Us creative director Neil Druckmann told Kotaku, "We screwed up." Naughty Dog thought it would announce the game before Uncharted 3 released, but when that didn't happen, it forgot about the hidden newspaper.
"We forgot about it. We should have taken it out," he said.
"These games are so big, right?" said game director Bruce Straley. "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."
Unfortunately for Naughty Dog, we were. It spilled its own secret.
The Last of Us releases on June 14 for PlayStation 3.