Batman: Arkham City will "almost certainly" feature clues pertaining to the third game in Rocksteady's series.
That's according to Official PlayStation Magazine, which makes the claim as part of a new interview with the studio's chief Sefton Hill.
The mag says it knows the rumour sounds "crazier than Harley Quinn on Christmas morning" - but that doesn't stop it asking Hill about the possibility.
"One of the key lessons we learned while making Arkham Asylum is that we always create a lot more story than will fit into a single game," he said.
"Although [Arkham Asylum] felt like a self-contained story, there are a large number of very deliberate hooks that lead into the second game... I don't believe in holding ideas back."
An Arkham Asylum Easter egg - containing loads of hints about what was coming in Arkham City - lay undiscovered until earlier this year.
Check out our latest preview of Arkham City to read about a game that is reportedly five times bigger than its predecessor.
The game is due for release in autumn next year.
Official PlayStation Magazine issue 51 is with subscribers now and will be on shelves this week. Order OPM here and have it delivered straight to your door.