Defeat Hotep

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. Travel through the time portal, potentially taking damage, to reach the future. Rearrange portals in the future to direct the laser into the target, then exit through the door.

Test Chamber 14: First, travel to the present using a time portal. Summon a reflector cube and position it in the designated area. Use a portal to guide a laser through the first node and then reflect it into the next two nodes using the cube. 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 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. Finally, position the future reflector cube 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 portal on the upper wall above the laser room to direct the laser to the first receiver. Travel back to the future and place a portal in the laser room to shoot at the receiver. Return to the present; the laser should power up an elevating platform. Stand on the platform and 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 and retrieve the future reflector cube. Bring it back to the present via a time portal placed in the laser room, positioning it to reflect the laser into the second receiver through the node. Now, get to the other side of the particle field without going through it (use a portal or time portal). 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 test chamber.