How to Beat Axja

Test Chamber 13: Place portals as shown in the image. Use a portal to move the laser sideways and a time portal to send it into the future. Travel through the time portal. Rearrange portals in the future so the laser hits the target.

Test Chamber 14: Travel to the present via a time portal. Summon a reflector cube and position it as shown. Use a portal to bring a laser through the first node, then use the cube to 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 passes through the node. Retrieve the future reflector cube and bring it to the present. Position the present reflector cube to hit all three nodes. Adjust as needed. Travel back to the future to retrieve the future reflector cube if necessary. Place the future reflector cube to reflect the laser into the receiver.

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 bypass the particle field in the future. Place another time portal to return to the present on the other side of the particle field. Place a portal on the upper wall to direct the laser to the first receiver. Travel to the future and place a portal on the small wall in the laser room to hit the receiver. Return to the present. The laser should power an elevating platform. Stand on it and place a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place the reflector 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 to the second receiver. Travel to the present on the other side of the particle field. Climb the stairs and place a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch.