Submitted by pchester:
There are twelve teleports, that I will call (TP1) - (TP12).
On arrival, head downstairs toward the control room. You hit the first teleporter (TP1) as you enter the room with the backpack in the "cage".
(TP1) takes you into the cage so you can see the backpack which is your goal. Move forward and hit (TP2) to be taken back to the first room.
Along the first corridor, creepy music and (TP3) back to the first room again (last time, honest!)
At the doorway out of the first room, (TP4) to middle of first corridor. You should be facing double doors that are slightly open. Turn right (back toward the entrance) & hit (TP5) which takes you slightly further along the corridor.
This time you go the other way (inward) toward the door with the keycode panel in the wall. At this door, (TP6) takes you to the room with the large circular tank. Head back out toward the exit until you hit (TP7) which puts you in the corner of the room with some machinery and stairs going up. (End of top floor bit!!)
Head back downstairs. Pass through the large room with two dividing walls. In the doorway to the corridor with the three small rooms, (TP8) sends you to the room just before where you hit the first teleport.
Move toward those steps and (TP9) to the corner of the room with three large bays and the stairs up to the control chamber. Let's call the end bay "Bay 3".
Head into the middle bay (Bay 2) and through the hole in the wall that takes you under the Bay 3 stairs, for (TP10).
(TP10) to the division between Bay 1 and Bay 2. Head into Bay 1, to the far dooway back into the cage room. In that doorway is (TP11) back to the cage room stairs where (TP1) was. Head back into the cage room and immediately hit (TP12) into...
THE CAGE! Pick up the backpack contents and get teleported out. All teleports done, now all you have to do is read the instructions and solve the code!