Unconventional Warfare

Test Chamber 13: Place portals as shown to redirect the laser. Use a time portal to move the laser into the future, then adjust portals in the present to direct the laser into the target. You may take damage from the laser to travel into the future.

Test Chamber 14: Start by traveling to the present. Summon a reflector cube and position it as shown. Use a portal to direct the laser through the first node, then reflect it into the next two. 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. If necessary, return to the future to retrieve the future reflector cube again and bring it to the present to complete the chamber.

Test Chamber 15: Begin 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. Return to the present using another time portal to be on the other side of the field. Place a portal on the upper wall to direct the laser to the first receiver. Travel to the future and place a portal in the laser room to shoot the receiver. Return to the present; the laser should power an elevating platform. Stand on it and shoot a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place this cube 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. Position it to reflect the laser through the node into the second receiver. To reach the third receiver, ensure you are on the present 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 chamber.