The first piece is very easy to find. When you first enter the Sewer area, you'll drop down into a room filled with water. Simply turn around after landing in the water, swim up to the surface, jump into the pipe, and the first PSG piece is right in front of you.

You'll get the second PSG piece during the section where you must stop the base from self-destructing. After turning off all missile silos and the big red button in the control room, return to the walkway that connects the main control room and the room that holds the control switches for missiles 3 and 4. Jump down into the missile silos themselves. At the bottom of one is the Bow upgrade, at the bottom of the other is the second PSG piece.

You'll see this piece high up on a ledge once you enter the Lab area. Don't worry about it for now, you won't be able to get it yet. For now, collect the fuses you'll need to turn the generator back on and flood the dam.
After you've flooded the dam, jump into the water and swim back down to the hole you used to enter the dam back when it wasn't flooded. You can swim back to the area with the PSG piece, which is now also flooded, and swim right up to it.

You won't be able to get this piece until the very end of the level. After defeating the Alpha Fireborn and taking the Fire Gem, ride the river to a lift that'll take up you back up to the temple. Some steps off to the left side will let you climb up the side of the temple and grab the fourth piece resting at the top. Mind the gap!

The final piece awaits you in the Gauntlet area, not long after you hitch a ride on top of the giant ore container. While riding the ore hauler, pay attention to the hexagon-shaped passages ahead of you. After the first room where Flesh Eaters take potshots at you, the ore hauler will pass by a little corridor to your right with some Life Force pieces. Hop off and follow them to a cracked wall that can be destroyed with explosive weapons.




Fight your way through a group of Flesh Eaters to a door that'll take you to a room with a huge power generator. Off to the right, nestled in the far back corner, is the final piece of the PSG.