Originally written and published for StropsE.com, written February 4th, 2021

Much like the wordplay in Who’s on First, the Memory module in Keep Talking and Nobody Explodes preys on miscommunication and, my greatest weakness, poor memory skills. Without a pad of paper to take notes, and a whole host of information that the defuser may not remember a couple steps down the line, this puzzle can waste a lot of precious bomb defusal time, and mistakes add up. So grab your paper and get ready to talk on the Subject of Memory.

Found on page 11 of the Bomb Defusal Manual, On The Subject of Memory is an early level module that requires some extra communication on the part of the Defuser. The entire puzzle consists of 5 separate stages, represented by the unlit lights on the right side. A large number will be shown on the display, which the Expert can use to figure out which button in each stage the Defuser should press. Buttons can be identified either by their relative position, with the leftmost button being the 1st, followed by the 2nd, 3rd, and 4th, going from left to right, or by their labeled number, 1, 2, 3, or 4. In order to fully disarm the module, you will have to progress through all 5 stages without any mistakes, as mistakes will reset your progress to the first stage. As always, it’s easier to show than to tell, so let’s say you start with this:

After identifying the game as Memory, and once the Expert is ready to record things (or just remember them), the first thing we’ll need to know is the displayed number.

Defuser: “The number is 2.”

Since we’re in stage 1, we want the Defuser to press the button in the 2nd position, which is labeled ‘1’. Make sure you note the position and label of the buttons you press in each stage, as those will be referenced in later stages. Onto stage 2!

Once the correct button is pressed, all the numbers in the puzzle shift and reset, with only the indicators on the right to show what stage you are on. 

Defuser: “The number is 1.”

The button labeled “4” is in the 3rd position going from left to right, so after noting it down, our Defuser can press the button labeled 4. 

Defuser: “The number is 3.”

Stage 3, display 3.

The button in the 3rd position is labeled “4”, seems easy enough. Stage 4!

Defuser: “The number is 4.”

…..aaaand this is where things can get tricky without taking notes. 

Stage 4, display 4 references the position of the button we pressed in stage 2. 

Remember, unlike other modules, you can’t step backwards in this one to see what you did previously. You have to rely either on your memory, your defuser’s memory, or whatever notes you took. However you chose to note it here, we pressed the the “4” button in the 3rd position in stage 2, meaning that now we press our 3rd position button here, which is labeled as “1”. Funnily enough, we’d do the same thing if the display number was 3 in this step.

Defuser: “The display says 4.”

Final stage! Round 5! Where are we looking this time? 

Hope you remembered to write down those labels as well as their positions! Here, the label in stage 3 was “4”, so we can just press the 1st button and solve the module. The final time you solve it, the numbers will stay the same, with only the light on the side and the green indicator changing to show the module is disarmed. 

There’s no real shortcut for this module overall, relying on memory is the name of the game, so the main trick is to take notes or only remember what’s important to solving. For example, you’ll never be asked what the display number in a certain stage was, only the label of the button you pressed and/or its position, so however you can best notate that for your own use is up to you.

As an interesting side note found while testing and writing this, the only part of the module visible when the lights are out is the display, so don’t go clicking randomly if you’re stuck in the dark for a bit. While you can solve some modules in the dark, this is not one of them, as it’s important to see the labels you click on. Please comment below what modules and puzzles we should cover next, or check out our other two guides for Keep Talking and Nobody Explodes. Now, to figure out who keeps leaving bombs all over the place…