Slush Fund

Test Chamber 13: Place portals as shown in the image. Use a portal to redirect the laser sideways and a time portal to send it into the future. Travel through the time portal, potentially taking some damage, to reach the future. Rearrange portals in the future to direct the laser into the target. Exit the chamber.

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 direct a laser through the first node and 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 reflector cube from the future and bring it to the present. Adjust the present reflector cube to hit all three nodes. If necessary, return to the future to retrieve the future reflector cube again. Position the future reflector cube to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Pass 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 the future to bypass 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 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 at the receiver. Return to the present. An elevating platform will power up. 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 by placing a time portal in the laser room. Position the present reflector cube to direct the laser to the second receiver through the node. Proceed to the other side of the particle field (in the present) without going through it. 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.