Battlefield 1” players recently solved a mysterious Easter egg in the game and uncovered what may be the reveal date for “Battlefield V,” according to Eurogamer.

The Easter egg is in a Conquest map called Fort de Vaux. It’s a mysterious door with the word “Isolement” written above it, which means “isolation” in French. Behind the door, players say they could hear a ghostly wail. Spooky! Members of the “Battlefield 1” subreddit and Discord chat spent a year puzzling out how to get it open. As of the game’s last patch, there’s now a way.

The process for opening the Isolement door is straightforward, but requires a lot of legwork, according to this YouTube guide by Westie. A number of signs scattered throughout the map have hidden buttons behind them. Each button has a letter that spells out “Isolement.” Players need to push them in order to unlock the door.

The room is empty. There’s no ghost, zombie, or other monstrosity. But, some ceiling pipes apparently drip out a bit of Morse code that spells out the following message: ea.com/neverbethesame

The hyperlink leads to a date, May 23, and the “Battlefield” hashtag. This is likely when publisher Electronic Arts will reveal the next title in the franchise, “Battlefield V.”

Yes, the reveal date has literally leaked.

“Battlefield” developer DICE has a long history of sneaking elaborate Easter eggs into its games. “Battlefield 4” players can trigger a giant megalodon shark on the Nansha Strike map, while “Battlefield 3” has hidden references to fellow EA titles “Dead Space,” “Mirror’s Edge,” and “Mass Effect.”