Speak With Teb

Test Chamber 13: Place portals as shown to redirect the laser. Use a time portal to move the laser into the future. Once in the future, rearrange portals to direct the laser into the target, then proceed through the exit.

Test Chamber 14: Travel to the present via a time portal. Summon a reflector cube and position it in the present as indicated. Use a portal to bring a laser through the first node, then reflect it into the next two nodes. Travel to the future. Use portals to bring a laser into the present through the time portal, ensuring it hits the node. Retrieve the reflector cube from the future and bring it to the present via a time portal. Position the present reflector cube to hit all three nodes. Return to the future. Place the future reflector cube at the end of the nodes to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Enter the particle field on the left. Place a portal where the laser hits the wall and a time portal on the opposite wall. Travel through the time portal to the future to bypass the particle field. Return to the present using another time portal on the other side. Place a portal on the upper wall to direct the laser to the first receiver, powering an elevating platform. Stand on the platform and place a time portal behind the node to raise it. Summon a reflector cube and place it on the lip above the second receiver. Travel to the future. Retrieve the future reflector cube and bring it to the present via a time portal in the laser room, positioning it to reflect the laser into the second receiver through the node. Return to the present on the other side of the particle field. Climb the stairs and use a portal on the upper wall to hit the third receiver. Finally, move the reflector cube onto the switch to complete the test chamber.