MAP STATS: (31)

Head down the stairs and enter the water. Find the first air vent (use these to replenish your oxygen level; if your meter runs out, you start taking 10 damage per second until you die).

Swim down the corridor to reach the next air vent.

To the right is a dead end with an RPG launcher. The left path continues the level.

Open the hatch by turning the wheel to the left.

Quickly head inside and stand on the vent.

Circle the room and prepare for a swarm of Octababies (dangerous underwater) to attack as you leave. Use your Shotgun or RPG (RPG recommended, takes 2-3 shots in the general direction) to eliminate them. Alternatively, lure them to a grate near the entrance by backtracking.

Swim onwards until you reach a ladder and climb it.

A checkpoint (an auto-save point you restart from on death) is reached. You can watch the Cycloid Emperor.

Use the pipe on the right to reach an EDF crate with two Laser Trip Mines.

Drop down into the next room.

A checkpoint is reached. A generator column will be hit by an RPG, taking out the lights. Turn on Duke Vision.

An RPG wielding Pigcop will spawn above you. Kill him quickly, as his RPG can be deadly in the confined space.

A bottle of Steroids is on the platform where the RPG Pigcop was. To reach it, go past the room exit, hop onto the pipes, and walk along the room edge to the platform. This is best done after clearing enemies.

An EDF corpse with a Pistol is in the semi-round walk at the far end of the room.

Eight Pregnators will spawn/hatch from Eggs (two at a time). Once defeated, the exit door will blow open.

A Shotgun Pigcop will jump into the room, followed by an Enforcer. Defeat the Pigcop and cautiously engage the Enforcer (freezing is recommended).

Enter the turbine room. A Ripper is next to an EDF corpse. In the pit is a body with a Holoduke beside it.

Shoot the red barrel (or carefully re-locate it) to open a new path.

Follow the corridor and stairs to the next level.

Before leaving, you can find a well-hidden Shrink Ray. At the far end of the generator room, there is a ladder to the catwalk above. The lower ladder was blown off. Stack three or four barrels (three regular barrels are in the tunnel leading to the end, or use exploding barrels safely) to reach the upper ladder. Arrange two or three barrels, jump on one, drop another between them, jump on the second row, and jump at the ladder until you grab it. Climb up and onto the catwalk to find a dead scientist with a Shrink Ray.