Quest For A Synthesizer

Test Chamber 13: Place portals as shown in the image to redirect the laser. Use a time portal to move the laser into the future. Enter the time portal yourself, even if it means taking some damage. Once in the future, rearrange portals to direct the laser into the target without affecting the present. Proceed through the door.

Test Chamber 14: First, travel to the future. Summon a reflector cube from the switch. Position it in the present in the designated area. Use a portal to direct a laser through the first node, then use the reflector cube to guide it through the next two nodes. Travel back 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. Ensure the present reflector cube hits all three nodes; adjust as needed. If you moved the future reflector cube, return to the future to retrieve it again. 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: Start by passing 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 now be hitting the first receiver, powering an elevating platform. Stand on this platform and shoot a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place this reflector cube on the lip above the second receiver. Travel to the future. Retrieve the future reflector cube and run into the laser room. Place a time portal in the laser room to bring the future reflector cube into the present. Position it to reflect the laser into the second receiver through the node. Now, you need to reach the other side of the particle field without going through it. Use an existing portal or a time portal to bypass it. Once in the present on the other side, climb the stairs and place a portal on the upper wall to hit the third receiver. Finally, move the reflector cube onto the switch to complete the test chamber.