To The Temple

Test Chamber 13: Place portals as shown in the image. Use a portal to move the laser sideways and a time portal to move it into the future. You may take some damage to travel into the future. Once in the future, rearrange portals so the laser hits the target directly. Proceed through the door.

Test Chamber 14: First, take a time portal to the present. Summon a reflector cube from the switch and position it in the present as shown. Use a portal to bring a laser through the first node, then use the reflector cube to direct 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 passes through 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. If it doesn't, adjust it. Travel back to the future to retrieve the future reflector cube if needed. Finally, place the future reflector cube at the end of the nodes to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Go through the particle field to 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 reach the future, bypassing the particle field. Head to the other side of the room and use another time portal to return to the present, now on the other side of the particle field. Place a new portal on the upper wall above the laser room so the laser hits the first receiver. Travel back to the future and place a portal on the small wall in the laser room to shoot the receiver. Return to the present. The laser should be hitting the first receiver, powering an elevating platform. Stand on the platform and shoot a time portal behind the node. This will raise the platform, allowing you to summon a reflector cube. Place this reflector cube on the lip above the second receiver. Travel to the future. Pick up the future reflector cube and enter the laser room. Place a time portal to bring the future reflector cube into the laser room in the present. Position it to reflect the laser into the second receiver through the node. Now, get to the other side of the particle field without going through it (use an existing portal or a time portal). In the present, climb the stairs and use a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch to complete the chamber.