Sometimes bands drop subtle hints about their future plans. Iron Maiden aren’t ones for subtlety, however. Their annual Christmas card that was sent out to their fan club members pictures their mascot Eddie running out of a building marked “Studio” with the card’s message reading “Eddie’s got a little Christmas gift for everyone who’s been REALLY BAD! Mus not be opened until 2015…” And to give fans a little something to argue over, there’s also a sign on the card with the somewhat mysterious message “UROTON 51.” That could pretty easily be decoded to read “On tour 15,” which many fans have already done.

Iron Maiden’s last album, The Final Frontier, was released in 2010. According to Blabbermouth, members of Maiden have been seen in Paris recently along with producer Kevin Shirley, who’s produced all of Iron Maiden’s albums since 2000. There hasn’t been any official word about the next album, which would be the band’s 16th, but it looks like this is a hint of things to come.