The start of the level finds you inexorably sliding into the entrance passage to the demon stronghold that is reverberating with the inhuman heart beat of the living walls.

Make your way to the end of the passage. Climb up the ledge and side-step to the right and walk to the edge, overlooking the bubbling lava. A high ledge is a run, jump and grab away. Pick up the shells from the crevice on the left.

Jump from the ledge back to the passage and drop down the hole. Go up the passageway and pause for a boulder to tumble into the lava. Jump over it and go through the natural archway into the large cavern and take a look around. A see-through wall to the left lets you view a later part of the level and what you will have to take care of.

Straight ahead of the entrance is a little crack in the wall. You are hindered by a small lava pool, but stand against the wall and a standing jump there and back will get you the medikit.

Pull your magnums or shotgun out and head into the cavern. Take out the demon on the left and head to where it came from. Grab the shells. Turn around to face the square building just in front of you. Walk to its left side and pull yourself up into it and drop down to the ledge below. Two flying demons will wake up - wait until you can hear their beating wings and then pull yourself up, and run back to the cavern.

Turn and dispatch both the demons. Return to the building's ledge and lower yourself down to collect even more shotgun shells. Now turn to look out over the ruined building. Before leaving this cavern you should collect a box of shells on the ledge directly in front of you on the other side of the room, while to your far right is a medikit and yet another box of shells.

Get the far box of shells first, jump diagonally forward and to the right. As you do so a boulder trap is triggered behind you but run for the middle of the cavern and it will be no trouble. A demon may attack you as you cross the cavern. In any case, head for the far side but be careful when you get there.

A gully runs down the side of the collapsed building and entering it sets off another boulder trap. Make your way around the gully to the three red columns that are in a row. Pull yourself up on the lowest one and retrieve the box of shells. As you do so another flying demon will appear so watch your step as you take it down.

Drop down and head over to the opposite corner to collect the medikit and shells. Once you have them turn around to face the collapsed building. A ramp leads up to the nearest square hole to you. Run up this ramp and drop down.

Face the new room you have entered. Two medikits are begging to be collected, each is just a standing jump over the holes in front of them. When it comes to exiting the room you need to drop down the hole currently to your right, the left one drops you to your death. Even the right one still takes half your health so top that up before dropping through.

After your fall, replenish your health before tackling this next room. There are four pedestals at the corners of the room with pickups on each one. Particularly nasty is the one right next to a demon pod - as you pick up the shells you see a new demon enter (via a cut scene). Stand still. Pick this demon off from where you are. As soon as you leave the pedestal the pod explodes, giving you another demon to deal with. Once you have everything, head for the door next to where you dropped in.

As you run up the ramp you activate a dart trap and a new demon behind you. Kill the demon and side step past the darts along the corridor to the right till you get to the spiral staircase leading down to a darkened corridor. Get your guns out as another demon is begging to be sent to an early grave.

Follow the corridor to the end where it comes out to a largish chamber with a staircase in the centre. There are also three inactive demons to the left with items behind. Don't try to pick those up yet. Instead, make your way over to the other side next to the see through screen and pull the switch.

This springs a demon centaur to life in the distant chamber. Turn around and head up the stairs, picking up the shells on the way. At the top you find five switches. The nearest two and the most distant one each activate one of the demons below.

When all three demons are out of the way, pull the final two switches at the top, collect the extra ammo and leave the room via the corridor. Halfway up the corridor a door has opened. In here are two demons and a bunch of ammo. Take out the demons from a ledge halfway up the slope. Once done grab the Uzi and magnum clips and shells then leave for the spiral staircase.

Head back into the big square room and cross to the right where a new doorway has opened. Get your guns ready, a demon awaits you at the top of the ramp. Finish it off and scramble onto the ramp at the top. Turn around and pull yourself up, do two backflips onto the ledge behind and away from the advancing lava.

Go up the left side of the chamber and as you reach the next chamber get your guns out and shoot the demon on your right. Make your way to the end and grab the shells and medikit from the other side. Go back all the way around the previous chamber to the top of the slope. Look to the right and jump into the gap there.

Make a dash around through the hail of blow pipe darts into a new large pool room, where two demons live. Whip out your shotgun and dispose of them. As you enter the room dive into the pool and swim towards the far submerged wall. Find and pull the two switches - this opens a door in the lower left of the room. Before entering take a breather and then go in to find ammo and medikits. Before leaving the pool room scout arond the bottom of the pool for a box of shells and another medikit.

Climb out of the wcter and head out of the chamber to the left. You enter a small room with a switch in the centre, pull the switch but ignore the two opening doors. Turn around and exit through the left doo. In here are two switches - one to the left and another to your right. As you pull the left Switch four demons are released.

Jump over to the stairs opposite and take your time dispatching the monsters. You will have to jump between the staircase and the floor opposite to lure the demons over, but apart from the odd fireball you should pick them off without any problems.

Before leaving this pool room dive into the water and collect the shells lying on the floor. Swim further down to find a switch and pull this to open a door at the top of the stairs. Climb out of the water.

You now have a few things to do before leaving through the door above. First, pull the second switch in this pool room. Go back into the small switch room. The two doors that opened have boxes of shells, along with a demon in each room. Finally enter the newly opened door from which the four demons attacked you, find the switch and pull it. This opens a door to your right, go through and pick the medikits up. Head back to the small pool room and climb the stairs.

You re-enter the large outside cavern from the start. A demon is going to attack you from the other side of the cavern. Once it is gone from this world head over to the newly opened door left of where you entered. Do not walk fully through the door as you will simply fall down into the pool below. Walk up to the edge of the door, a demon is lurking just to the left but it cannot get to you as it is stuck on a ledge. Pick off the demon and then drop down.

Once in the water find the couple of magnum clips lying around, before turning your attention to the switches that are next to each other. Pull the one on the left, this opens a submerged door over to the left. Get in there and grab the shells and Uzi clip and then swim back out. Get out of the water using a ledge to the left of the switches. Climb up to the left and pull the switch that you come to, this opens a door above your current position. Turn to your left and perform a jump/grab for the opposite ledge. Spin around and see a box of shells on a ledge to your right, just run across to it and then jump back.

You now need to pull yourself up onto the ledge where the demon you killed (before falling into the pool) was standing. If you did not kill the demon it will currently be pounding you with fireballs. Once up, jump over to the medikit and jump back again. You should see two doors, the one to the right is the one you came in through, the one on the left you opened just before with the switch. Carefully line yourself up with the doorway on the left and make a standing jump over to it.

You find yourself at the top of a room with a floor covered in spikes, so watch your step. The first move is a dangerous run and jump made diagonally left over the pit of spikes to a ledge slightly lower than your current position. Turn right around and walk onto the slopping ledge, pull yourself onto the ledge on your left to retrieve a medikit.

Climb back down and make a running jump over to the ledge with magnum clips on it. Step off the ledge backwards and grab the edge, let go and quickly grasp the crack just below. Shimmy to your right and drop down to get another magnum clip. Climb up the next block.

Drop off the end of the block to the ledge below and then drop into the only spot without spikes. Walk to the far-left corner of the room to pull a switch. This opens an underwater door, walk back collecting the medikit on the way and jump in the water. Follow the tunnel round to appear back in the original chamber with two switches. Swim back collecting the box of shells and magnum clips if you missed them first time.

Climb out of the water and walk over to the right and pull yourself up onto the red patterned block. Pull yourself up to the block on your right and turn around to face the slightly higher ledge opposite. This is a tricky jump and grab. Once you make it spin around and make a running jump to the ledge opposite. Climb up onto the ledge to view the next room ahead.

Make a running jump over to the far side of the room, get your shotgun out as you reach the middle of the room, as a demon jumps out from the left corner. Walk over there to find some magnum shells. Before you pick them up, face the opposite wall. As you pick them up another demon appears so take care of it, before collecting the box of shells.

Make a standing jump to the rock bridge, running across the room and climb up the end to enter a new tunnel. Jump over the two sections of lava and collect the boxes of shells at the end of the tunnel.

Turn around and make your way a couple of squares down the tunnel. Climb up to a hole in the wall on your right. You are, yet again, in the large cavern. Jump over to the fairly large ledge opposite.

Two flying demons will come in around the right side of the cavern. When they're dead perform a running jump to the ledge with the magnum clips on and then jump back. Stand on the slightly raised section. Looking over the collapsed building you need to make a running jump into that right hand hole. Get it right and you slide straight in.

After a rather long fall you land in pool of water patrolled by the centaur activated much earlier. Climb out and take it out then pull a switch to end the level.