The last corridor is a room that is opened after deciphering the morse code from the radio and typing the code that you get in chat.
This room contains a door and a pad with base 16 code on it - hexadecimal code - this code is used to change the top line of numbers on the pad into the correct code to type the code in chat.
An example
This code can by worked out through that there are only 2 numbers in the 30s in the entirety of the base 16 code - this means that those two numbers are two of the three numbers of interest (NOI), with the third NOI being the top code.
The FIRST NOI ALWAYS appears in the top line - in this case it is 31 - this means that we can use the number to work out what number we need to replace in the top line, which is 1.
Then the SECOND NOI ALWAYS appears in the bottom line - in this case it is 38 - this means that 8 is the number that we must replace the 1s with.
Replacing the 1s with 8s gives the code 8974024.
After finding the code, the player must type it into the chat to proceed to the next stage.