|Test Chamber 03|
|Name||Test Chamber 03|
|Quests||You Had One Job!|
Portal This Test Chamber is the fourth level of the game and introduces the player to the basic principles of portal-placement.
Chapter 1: The Courtesy Call These chambers form the fourth level of the game, and take place within two separate dilapidated Test Chambers. The two Test Chambers introduce the concept of using multiple Weighted Storage Cubes in conjunction with intermediate Portals, as well as utilising the Aperture Science Handheld Portal Device to obtain objects that would otherwise be inaccessible. These two Chambers correspond to Test Chambers 04 and 05 from the original Portal. Chamber 04 features a Rat Man den, which is decorated with a number of his trademark murals.
Chapter 2: The Cold Boot This is the twelfth level of the game, and takes place within a dilapidated Test Chamber. This level introduces the player to multiple Thermal Discouragement Beams within a single chamber.