Portal 2 Chapter 1 Test Chambers 3 & 4

These chambers form the fourth level of the game; introducing the concept of using multiple Weighted Storage Cubes to open a door via intermediate portal control.

Hazards
None

Walkthrough
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Chamber 03

 * When entering the chamber, observe the Weighted Storage Cube falling into the pit. Either fire a portal below the cube, or jump down and then fire a portal at a wall and then carry it through, to bring it to the upper level.
 * Place the cube on the Heavy Duty Super-Colliding Super Button; proceed through the door into chamber 04.

Chamber 04
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 * Observe the orange portal on the platform across the room; place a portal and walk on to said platform.
 * Place a portal on the opposite platform; it is now possible to acquire the cube through the orange portal. Place the cube on one of the buttons by the door.
 * Opposite the door will be a pit containing a cube; fire a portal below the cube at the bottom of the pit to place it on the platform with the orange portal. Follow the cube through this portal or through a new portal on your current tier, whichever is most convenient, and place the cube on the remaining button and walk through the door.
 * Look up to observe an orange portal through the glass; place a portal on one of the surrounding walls and walk through it to land on top of the glass.
 * Turn around and walk through the destroyed section of wall to reach the chamberlock. Inside this wall section is a staircase that leads to a Rat Man den.