Backtrack about halfway along the enclosed walkway to the 2 red wheels.

Each of these opens one of the metal doors in the cave outside, letting in 2 huge mutant fish. If you like, you can turn the wheels one at a time so you don't have to deal with both fish at once. I was hoping they'd fight each other, but they don't.

Follow the enclosed walkway back to the main corridor. Turn right...

...then right again through the yellow door into the COMPUTER ROOM.

Drop through the trapdoor into the pool.

Then swim down...

..and harpoon the 2 mutant fish.

If necessary, swim back up through the white funnel to get air at the trapdoor opening, but remember that you can't climb out of the water here.

- OR -

If you're out of harpoons or just need an alternate strategy, try this: After dropping through the trapdoor into the pool, turn around to face the white building. Then swim to the far right corner and through the small, square opening underneath the rusted metal support. Turn left and swim upwards.

Surface here and pull up into the corridor where you killed the gunman.

Then shoot the fish with pistols from above. You may have to jump back into the water and swim out into the cave to get the other fish's attention, but this strategy should work just fine with a little patience.

[Part 1 | Return to the Sleeping with the Fishes Walkthrough]