Quake II/Lost Station

Lost Station
The Lost Station is a secret level, where your objective is to find a powerful shotgun. While it will help you, the weapon can also be found in the final room of the Installation, giving an advantage only for one level.

Upon exiting the elevator, you should see the shotgun to your left. Walk down the corridor until you see the cargo lift; if desired, you can collect a machinegun to your right, if you don't have the weapon already.

Ride the cargo lift to the second area. Go through the door, and when you reach the stairs, turn around and shoot the button. This allows you to collect the red key. Continue along the original direction of the stairs.

At the end of the path is a watery cavern with a central spire. Take the life on the side, and use the red key to lower the bridge. When you collect the double-barrel shotgun, the level is complete, but enemies will appear throughout the level as you return to the exit.

Secrets
This level has six (6) secret areas:
 * 1) Upon entering the first cargo lift area, head to the room on the right.  Jump up to the top of the crates and drop down behind them to find a Silencer.
 * 2) In the first cargo lift area, jump into the water.  Swim to the left and find the underwater entrance to a corridor containing a Rebreather and various other items.  The corridor ends at a door leading back to the entrance to the first cargo lift area.
 * 3) An adrenaline can be reached by shooting a wall button.  This opens array of wall-mounted shooters.  Jump down and into the door on the left to reach an Adrenaline.
 * 4) In the second cargo lift area, dive into the water.  Shoot the wall button to the left to open a secret door in the opposite direction.
 * 5) Below the panel leading to the double-barrel shotgun, there is an underwater door at the base of the tower.  It contains two Barracuda Sharks and leads to an Invulnerability.
 * 6) The wall button that raises the ramp to provide access to the Red Key Card also reveals a secret area under the ramp.  If you stand just below the button as you shoot it, you can jump off the ramp before it rises, then turn around and run into the secret area beneath it.