That ending raises more questions than it answers, like everything else about Signalis, but it does offer a new perspective on the game’s notoriously dreamlike storyline.
Naturally, this cannot realistically be discussed without heavy spoilers for the entirety of Signalis. Beat the game on your own at least once before you continue reading this piece.
How to Unlock Signalis’s Secret Fourth Ending
This isn’t so much a guide as it’s a guide-shaped news piece. I can honestly say I’d never have found any of this information on my own.
Since Signalis went live, fans have contributed to a long-running thread on Steam to try and figure out more about the game’s various endings. Many of them started digging into one big unsolved mystery.
On two occasions during a normal run through Signalis, you end up in Ariane’s old bedroom in Rotfront, in first-person mode. You can explore a bit while you’re here, and if you turn right and look down, you’ll spot a triple-locked safe in the corner of the room.
Fans went through the game with a fine-tooth comb for a few days trying to figure out how to open that safe. The turning point was when someone found a seemingly pointless broadcast on the in-game radio and ran it through an SSTV decoder.
This isn’t as random as it might sound. SSTV (slow-scan television) is often employed by people who make alternate-reality games, such as the one that’s hidden inside Portal, and there are a lot of seemingly meaningless broadcasts that you can pick up with the radio at various points in Signalis. If you know what SSTV is in the first place — and I didn’t before this — it seems like something you’d naturally think to check.
Following that first breakthrough, fans of Signalis quickly tore through the game looking for any other strange SSTV signals on the radio, and found them. Three broadcasts turned out to decode to specific images, which corresponded to three locations found in-game.
When you visit those locations with Elster’s radio implant active and tuned to the SSTV signal’s frequency, you can find three hidden keys that will open the locks on the safe in Ariane’s room.
The Key of Love can be found in Isolation on Floor B2 of the Sierpinski facility, early in the game. Tune your radio to 096.000 and check the lower right-hand cage.
It may take you several tries to hit the specific point on the cage that you must interact with to find the Key, which very well could be a bug.
The Key of Eternity is in the darkened bedroom on Floor B8 of the Sierpinski facility. Tune your radio to 065.000 and examine the bookcase in the back of the room, underneath the low-poly recreation of Goya’s Saturn Devouring His Son.
You’re going to have to shoot your way in, as 4 corrupted Replikas are between you and the Key, and you’ll need the flashlight module so you can see what you’re doing.
Finally, the Key of Sacrifice is in Rotfront, in the Backroom behind the bookstore. Check the conspicuous row of white books just left of the center of the room while your radio is tuned to 240.000.
After some testing, I’m also guessing that none of the Keys will appear at all unless you’ve cleared Signalis at least once. I was able to get the Keys to appear with a minimum of hassle on my Steam installation of Signalis, on which I’ve beaten the game. However, the Keys did not appear to be available at all when I played through a first run of Signalis on Xbox Game Pass.
You can and should immediately throw all three Keys into your item box and leave them there until right before you solve the moon dial puzzle in Rotfront. Once you’ve opened the tunnel to Ariane’s room, backtrack to grab the Keys before you enter. If you don’t have the Keys on you when you go down the tunnel, you won’t be able to use them on the safe, since the tunnel back to Rotfront closes behind you, and Elster refuses to reenter Ariane’s bedroom once she’s left it.
Once you’ve gotten the three padlocks off of the safe, you still have to input a code to open it. This code is 39486 60170 24326 01064, which you may recognize as the random string of numbers that you overhear on Ariane’s radio at the end of the prologue.
Opening the safe in the bedroom immediately triggers the hidden ending and skips the last boss. It has no particular rewards or achievements attached to it.
Other Endings
On your initial run through Signalis, you’ll get one of 3 endings after your fight with Falke: Leave, Memory, or Promise. It was initially a complete mystery as to what determined which ending you got, although there were a lot of theories and rumors on the subject.
Eventually, someone gave up and went datamining for answers. It turned out that the overall criteria for the endings are a little more obvious than a lot of fans thought they were, and largely revolve around your style of play.
To get Leave, act as if Elster is reluctant to finish the game. Pause to exhaust every NPC’s dialogue, try to open every broken door you pass, heal immediately every time you take damage, and linger in the post-Nowhere Penrose flashback level for at least 5 minutes.
To get Memory, play the game as a typical survival-horror veteran might. Keep your time on the clock as low as possible; don’t kill anything you don’t have to; take minimal damage; and clear the game in 6 hours or less. Notably, every speedrun attempt on Signalis seems to get the Memory ending.
To get Promise, go on a killing spree, as if Elster is unwilling to let anything stand in her way. Shoot and “kill” at least 120 enemies; take a lot of damage; die at least 6 times; and spend over 12 hours in-game before you complete it.
These are not hard-and-fast rules. According to the behind-the-scenes math, you start with 2 points towards Memory, and must earn enough points through your actions over the course of the game to overcome that initial bias.
Now, if you want to figure out what those endings mean, your guess is as good as ours. If you need more help with the game, check out our other Signalis guides.
