Bolt Cutters

Test Chamber 13: Place portals as shown to redirect the laser. Use a time portal to move the laser into the future, then rearrange portals in the future to direct the laser into the target.

Test Chamber 14: Travel to the present and summon a reflector cube. Position it to redirect the laser through the first node. Travel to the future and use portals to bring the laser back to the present through the node. Bring the future reflector cube to the present and position it to hit all three nodes. Finally, travel back to the future to place the reflector cube to direct the laser into the receiver.

Test Chamber 15: Start by going through the particle field to the left. Place a portal where the laser hits the wall and a time portal on the other wall. Travel through the time portal to the future to bypass the particle field. Return to the present on the other side. Place a portal on the upper wall to hit the first receiver. Travel to the future, place a portal on the small wall to hit the receiver. Return to the present; the platform will rise. Place 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, pick up the future reflector cube, and bring it to the present using another time portal. Position it to reflect the laser into the second receiver. To reach the other side of the particle field, use a portal or time portal. 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.