In the Swan hatch, the computer program had to be activated every 108 minutes. The station’s occupants entered the sequence 4, 8, 15, 16, 23, and 42 before the countdown reached zero.
The procedure was introduced in the Swan’s orientation film, presented by Dr. Marvin Candle. The film explained that an earlier incident had made the station dangerous and that the computer protocol was necessary to prevent another catastrophe. Desmond Hume had been performing the task alone when the survivors found him.
The 108-minute interval is not the same as the number sequence. The numbers were typed into the computer, while 108 minutes was the repeating time limit. This distinction is a common source of confusion, especially because the numbers add up to 108.
When Locke eventually stopped believing the procedure mattered, he prevented the computer from completing the countdown. Desmond then used the failsafe key, destroying the Swan and releasing a powerful electromagnetic discharge.