Sam Fisher- Thermal Code

  It’s an empty reception office. A door with keycard access leads to the rest of the warehouse. I drop the goggles over my eyes and activate the thermal-vision mode. I’m in luck—someone very recently went through the door. The keys most often punched show traces of residual heat as long as not much time has elapsed. The trick is to press them in the correct order. Logically the key that’s the faintest would be the first one and the brightest key would be the last. Distinguishing the differences of luminescence on the three keys in-between is the hard part.

  On this particular pad only four keys show heat. That means there are only four numbers in the code or one of five numbers is used twice. I’ll need a little help with this one, so I aim my OPSAT screen at the keypad and snap a shot. I then use the controls on the OPSAT to play with the contrasts in the image. This gives me a digital readout of the amount of luminescence it’s picking up. The 2 key is the brightest, so it’s either pressed twice or it’s the last of four numbers. The 4 is the next brightest, followed by 8 and 3.

  I try 3, 8, 4, and 2. Nothing happens.

  I try 2, 3, 8, 4, and 2. Nothing happens.

  I press 3, 2, 8, 4, and 2. Nothing happens.

  I punch 3, 8, 2, 4, and 2. Green light. The door unlocks. I’m lucky the system doesn’t set off an alarm after three unsuccessful tries, which many do.

- Splinter Cell, Chapter 16