It’s 2020, so even the Doom Slayer gets his own personal computer in Doom Eternal. But if you’re exploring the Fortress of Doom in Bethesda’s new hardcore first-person shooter game, you’ll need a secret password to access it.

The solution is a deep-cut Easter egg from the much older games in the series. Can’t figure it out? We’ve got you covered.

The sprawling Fortress of Doom is a spaceship that looks like a massive floating castle. Within its labyrinthine walls are a variety of rooms you can unlock with Sentinel Batteries to access special perks, a “Ripatorium” where you can murder a bunch of imprisoned demons, and Doomguy’s bedroom. The castle is loaded with Easter eggs from the Doom series, and the computer in his room is one of the biggest.

On a table, there’s an old-school PC displaying two hidden files. The first is unlocked once you beat the game and have collected all 14 Floppy Disks. (Spoiler: It unlocks the game file for the original Doom (1994), which you can play using this console.) The second requires a 12-digit passcode to access. So what’s the password?

This other file can be unlocked by punching in “FLYNNTAGGART” to gain access to Doom II.

In the ancient era of 1995, Doomguy had a real human name in a series of novels: Flynn Taggart. These books were based on the original games but deviated from established canon. At one point, a copy of Taggart’s consciousness was uploaded into a simulation that forced him to play through the events from the first two Doom games on an infinite loop.

While this password is mostly just a fun nod to the books, it could also mean that in the new continuity of 2016’s Doom and now Doom Eternal, the Doomguy’s real name is indeed Flynn Taggart. That could also mean this janky old PC is possibly the one that Taggart is trapped in. By now, however, our Doomguy is an angelic, superpowered, immortal demon slayer who can’t even speak, so none of that really matters anymore.

Doomguy plays the original ‘Doom’ games on this PC.Bethesda

Sure, using your own full name as a password is a terrible idea from a security standpoint. Thankfully, this computer probably isn’t connected to the same network as the rest of the ship, and only makes use of these offline games.

There are some reports of Doom Eternal crashing when some players try to activate Doom II, but in a game chock-full of self-referential Easter eggs from earlier in the series, this is perhaps the most exciting one.