Upon solving the Pump Controls puzzle on level B3 in Signalis, players can drop into the Flooded Bathroom on level B4. The Flooded Store Room is situated very near to this Bathroom, and fans will find a Blank Key within it. This Blank Key plays a significant role in one of Signalis's puzzles, and this guide contains full details on its solution.
Signalis: Blank Key Puzzle Solution
The first step toward solving the Blank Key puzzle is to visit Imaging, a room that is accessed through the North Corridor that is situated down and to the right of Reception on B3. In the Imaging room, fans will encounter an X-Ray that can be used to examine several objects that are behind glass. The object that is relevant to this Signalis puzzle is object D, and players should press the D button on the right, click on the monitor, and toggle the image mode to activate the x-ray.
Upon performing these actions, fans will discover that there is a keycard lodged into the object. Signalis players should now rotate the object so that the keycard's cut corner is at the bottom-right and then take a screenshot or use the Eidetic Module to make a picture. Alternatively, fans can simply reference this image, which depicts the keycard that is embedded into object D in its correct orientation:
Players should now make their way to the Office that is just above Reception on B3. There is a Card PC in this Office, and fans should insert their Blank Key into it and select Define Pattern on the monitor. Players should then recreate the pattern that appeared on the keycard from Imaging, select Print Pattern, and remove the altered Blank Key from the terminal. Notably, survival horror fans will not receive indication that they have solved the puzzle at this point, though they can be confident that they are on the right path if their Blank Key matches this image:
With the altered Blank Key in hand, players can head to the Waiting Room, which is through the East Corridor below Reception and to the left. There is a door that is opened with five keycards in this room, and indie horror fans should insert the Blank Key into the slot that is marked with an E. Fans can then proceed through the door if this was the last of the requisite keycards or focus their efforts on finding any keycards that are still outstanding.
Signalis is available for PC, PS4, Switch, and Xbox One.