E4M1: Catafalque (Heretic)

E4M1: Catafalque is the first level in The Ossuary episode of Heretic Shadow of the Serpent Riders.

Strategies
This is easily the most difficult level in the fourth episode, probably the whole game, due to the general lack of ammunition. The Black plague difficulty could possibly be easier than the smite-meister difficulty for some players, since the former adds 1.5x the ammo but does not increase the enemies' health. However this is unlikely without great skill, since enemies may need to be dispatched more quickly, and that makes patient use of the central crusher less feasible.

It is extremely challenging to kill everything before you're only left with melee weapons, in any given stage and for the level as a whole. For a more reasonable and enjoyable challenge, kill what you must, and leave what isn't worth killing. Leaving the Maulotaur in the courtyard is one thing that will make the rest of the level much easier, although obviously, this is extremely unsatisfying since killing maulotaurs is great.

For those that desire 100% kills, some tricks can still win out. Exhausting the tome in combination with the gauntlets can just kill the Maulotaur in time. Even if 100% kills are not required, ammo will be short for most of the level, but fortunately, due to the large number of runes lying around, the ammo shortage should be greatly alleviated when the player comes across the Hellstaff. (Those aiming for 100% will still need to be prudent though.)

If you can stretch your resources to killing everything in the level, you should still be able to recover well at the beginning of the next level, so feel free to use everything you have.

Possibilities for monster in-fighting are limited, except in the outside courtyard. Releasing too many enemies of different types, all at once, will cause overcrowding, and probably requires more use of ammunition than patient use of the crusher would.

Walkthrough
This walkthrough assumes that the player desires 100% kills on smite-meister difficulty, and must use extreme ammo conservation to achieve it. This is somewhat tedious, as it relies on extensive use of the central crusher, and it can be tricky to coax enemies under it, due to the 'random walk' component of their motion. It is probably not a suitable method for black plague difficulty, because it is rather slow.

The author of the walkthrough section has not completed the level without extensive use of the save/load feature. If you have done, please consider submitting improvements.

The player starts facing north. To the left and right are short corridors with crystal vials and a silver shield -- the only armour in the level. Choose carefully when to pick it up, and beware that initially, these corridors are filled with gargoyles.

Proceeding forward to the visible but inaccessible green key draws many gargoyles into the room behind, gives the player an ethereal crossbow, and activates the very useful central crusher. It will not be possible to coax all the gargoyles under the crusher, since they will crowd the player; using some ammunition will make the job a lot easier. The staff can be effective in a tight space, but watch your health as there are limited vials and flasks available in the level. If the player can dodge the gargoyles sufficiently to avoid killing them, it may be possible to proceed to the next section of this walkthrough, and hope for some extra monster infighting in the courtyard, as a result.

When the room is clear enough, find the switch in the south east of the room; this slightly lowers the wall of the outside balcony, allowing outside access, and a route to the yellow key. It is situated at the south west, or to the left of the building ahead of the player, while jumping from the balcony. At the north east is a small room with a teleport, and this is the only route back. First it leads to a closed room in the central building, with some gargoyles and a central pillar to run round while trying to take them out, again with a minimum of ammunition.

Opening any one door in the outer walls will cause all four to open at once, greeting the player with many ophidians and gargoyles together. Stepping through onto the outside ledge lowers the central pillar to reveal the second teleport; it will lead back to the balcony of the main building, facing indoors. (If the player has to jump off the tower to escape many attacks, it does not matter. Reusing the first teleport is an easy way to reach the second one, which is directly in front of the first's destination.) Staying on the ledge for long enough to reach the corners can reward the player with three quartz flasks and a morph ovum that might save a lot of ammo if it is used well.

Yellow Door
Proceed through the yellow-keyed door, and allow some use of ammunition on the horde behind it. Again, the crusher is difficult to use on so many enemies. To the left and right (north and south) are two staircases leading upwards, and in the centre is one leading down to another door. Beyond this door is a small room with a green keyed door, and a switch on the right hand (southern) side that opens two alcoves towards the top of the upward staircases. Ascending either staircase after using the switch will probably alert disciples beyond the northern alcove, but they are reasonably easy to coax out one at a time, towards the crusher room. (Two can be dealt with but one is preferable.)

Skilled use of the crusher starts to become more important, and it is helpful to understand the monster AI here. Any awakened monster will at all times move generally towards the player, wherever the monster and player are in the map, except that monsters also have a 'random walk' component added to the direct motion. Different speed weightings may apply to the two components for different monsters. For instance sabreclaws have a large/fast random walk, making them difficult to herd.

Enemies will wander under the crusher more frequently, and die sooner, the more directly you cross the room, and the closer you get to the crusher yourself. Therefore running under the crusher can actually carry less risk in the long run, than avoiding it. Running quickly around the edge of the room, turning to check on the position of the disciple(s), will usually result in needing to run much further than anticipated, to find oneself diametrically opposite to them.

Continuing through the alcove on the northern staircase is not necessary for a speed-run, but will give the player some useful items including a quartz flask, and ammo-saving bombs; there is one disciple around a corner, next to a switch and a quartz flask, who won't have been woken yet. The switch lowers the platform that the quartz flask is sat on, and leads to a safe, enemy-free tunnel filled with timebombs of the ancients, and ending in the small room with the green door and switch, where the player has already been. If you've avoided the use of time bombs so far, this might be the level to learn the knack. The player must run away immediately after dropping one, so too much overcrowding can be dangerous; yet they are most effective when used on a cluster of enemies. The door of a monster closet that's about to open can be a good place for a near-guaranteed strong hit. Use with discretion!

The southern alcove, unlike the north, is necessary for progress in the level. It has a floor full of sabreclaws, where some ammo is almost certainly required, but which is also a good testing ground for a time bomb, especially straight after landing. In the north west of the room (behind the player and to the right, on entering the room), is a switch that raises a nearby section of staircase. Climbing the stairs, activating each new section with another switch, leads to an alcove containing the much needed gauntlets of the necromancer; however, collecting them will set off a bigger monster trap than the player is likely to deal with well at this time. Pushing forward into the gargoyles, ignoring the disciples behind, may work but will cost a great deal in health; escaping to the crusher room is more tedious, but is more likely to be survivable.

Maulotaur
If health is very high, consider activating and dealing with the monster trap now; the next stage is to deal with the maulotaur by combining the gauntlets with a tome of power, and this is actually wasteful to do from high health, since it replenishes the player so effectively. If health is still high, consider opening secret 1 at this time; it opens another monster closet with yet more disciples, the passage back to the starting room contains some more sabreclaws, and entering the starting room from the passage will open two walls to reveal a cluster of gargoyles. Each group of enemies can either be dealt with now, or left for later.

After reaching the top of the steps, before collecting the gauntlets, notice that a lift lowers at the room's entrance. This is temporary, but it can be repeatedly activated, and will also activate when the player runs out of the gargoyles' alcove and off the staircase. Choosing to leave the room before activating the monster trap affords the opportunity to prepare an alternative escape route. An alcove will have opened at the top of the northern staircase, containing a switch that opens a corresponding alcove at the top of the southern staircase. This contains a teleport, leading to a very dark tunnel full of ophidians. If health is already low, it may be advisable to open the teleport, return for the gauntlets, then escape quickly via the lift and the teleport. (This also gives an additional benefit of leading disciples to the outside area, which may cause some valuable monster infighting.) To the right of the player, at the tunnel start, is a tome of power. At this stage it seems almost essential, for getting past the ophidians that will wake up as you proceed down the tunnel. However, secret 2 is accessible without killing anything, albeit with some probable damage. Don't worry about the damage, as it will soon be replenished. Water runs in/out of this area through two letterbox openings; the player starts next to the first, and should proceed quickly past the second before searching the right-hand wall for the secret.

The teleport destination is on top of a high ledge, above the outside area with the maulotaur. Collect the powerups here, then ready the tome of power and the gauntlets, and jump off. You will have a very short time, after activating the tome, to locate and attack the maulotaur. You will almost exactly use up the tome in the time it takes to kill the maulotaur, during which time you will probably get surrounded by sabreclaws, and pummeled by ophidians and disciples; yet the combination of tome and gauntlets will keep you practically invulnerable. When the maulotaur dies, escaping the horde with 100% health is unlikely, but this author was up to 75%, from 13% before the fight, and happy. The screen was too obscured by red to see for sure but health may even have been 'bouncing' off zero. No movement controls seem necessary to continue attacking the maulotaur; it appears to be 'held' by the gauntlets.

Further progress requires the green key. Return to the main building via the teleports, dealing with any crushable enemies when you get there, and return to the dark ophidian tunnel. The enemies should be more spread out now, and dodging round the corner (towards the letterbox opening) is now much safer, since there is no maulotaur to see you. Some ammunition may still be needed, to proceed all the way past the enemies, to the end. A lift lowers when approached, giving the player a dragonclaw and an escape route. Drop down onto the green key, and beware of more ophidians in the crusher room, since the four outer pillars will have now descended. This makes it much more feasible to herd things into the crusher, without getting overcrowded. (Ophidians will probably still require some ammo, however, since their attacks can be so damaging, and quick dispatch is desirable.)

Green Door
Beyond the green-keyed door is a corridor with a hellstaff (at last!), and also six alcoves, each containing a gargoyle. Do not get carried away using ammunition now that you have a meatier weapon; resources are still tight.

The gargoyles are now easy to crush, if coaxed out two at a time, but killing them flawlessly with the gauntlets is unlikely, as they are fire gargoyles. The middle, right-hand (southern) alcove has a door that can be opened, hiding a sabreclaw. Crossing the threshold of this door will open similar doors in the other five alcoves, all with sabreclaws. Simply running in circles around the now nearly empty crusher room should be sufficient to herd the sabreclaws under the crusher, while a more systematic approach can actually be more frustrating, due to their largely randomised motion. Also, sabreclaws often get stuck at the sides of the main staircase, instead of following up to the crusher room, and this usefully limits the number that need to be herded at once.

When all six sabreclaws from the alcoves are dead, return to the middle/south alcove that opened the others, and activate the switch there. A teleport is revealed in the opposite alcove, and the door to the exit room opens at the east end of the corridor -- to the right as the player leaves the alcove. The teleport simply leads to the outside balcony, escaping the iron lich that was waiting behind the door to the exit room. A more useful teleport is also revealed, but is less obvious. Dare to turn right, towards the iron lich, and find the north-east alcove, instead. It has a teleport, with a ring of invincibility. It is only necessary to go through if you want 100% kills and/or 100% secrets, but if that is your aim, then this is probably the best time to go through. It leads to the first of four ophidian cages surrounding the exit room. They are visible from the floor of the room but trying to kill them from there would surely waste too much ammo. Fortunately, the ophidians have probably not woken up if the teleport was taken at the first opportunity, and will be facing away from the player, allowing a brief respite and item selection. Using the ring of invincibility here is advisable, or a well timed chaos device if there are still ample health powerups elsewhere.

The final teleport leads back to the south-eastern alcove, opposite the north-eastern alcove that the trip started from. The player is unlikely to kill all the ophidians before the ring of invincibility runs out, and will have to choose between emptying the first two or three cages then attempting the last cage(s) while vulnerable, and the plan of delivering limited damage in each of the four cages. Some experimentation suggests that the former plan results in less damage to the player in the end.

In the exit room, to the right/south there is a door that will only open in response to triggering a linedef at the edge of the room's central pit. If you fall in, you're going to have a bad time. There are four iron liches down there. Activate the switch behind the door that opened, and the opposite door opens, releasing a largely irrelevant sabreclaw. Activate another switch, and the final door opens at the far end of the room, revealing the final switch and another somewhat doomed sabreclaw. By now the iron liches will have almost surfaced, so it's time to see if you've saved enough ammo to kill them, and anything else you've skipped. Try not to step on the raised platform once the liches are out, since some ports will allow the floor to rise again, making the exit inaccessible.

When everything is dead, or when you're fed up with crushing, tickling and yelling at your enemies, use the final switch to lower the exit port, in the centre of the platform that raised the iron liches. Any floor-raising bug will now be cured by the lowering of the central sector.

Enjoy the next level; it has ammunition! In fact it has plenty of everything, and you should proceed even if you are nearly dead; your resource problems are now over.

Secrets

 * 1) Once you get the gauntlets, a small opening is revealed on the west side of the room, releasing Disciples of D'Sparil.  This opening has a secret door which releases more disciples, and leads to a passage containing a single greater runes powerup, and some sabreclaws. The passage leads back to the starting room.
 * 2) The dark, underwater lake to the north (with all the ophidians) has two impassable openings to the south, which lead to the tower courtyard. To the east of these openings, on the south side of the room, is a secret door which leads to a teleport. The teleport takes you to a high ledge with a chaos device and some claw ammo.
 * 3) After you hit the switch opening the exit room, find the north-east alcove, where you will find a ring and a teleport, which takes you to the cages surrounding the exit room. The first cage is tagged as a secret.