MAP17: House of Thorn (Memento Mori)

MAP17: House of Thorn is the seventeenth level of Memento Mori. It was designed by Eric Sambach, and uses the music track "Dreadnaught" by Mark Klem.

Essentials
Blue Key

From where you begin, walk forward and open the metal-plated wall in front of you. Clear out the two shotgun guys in this room, then find the skull switch in the shadowed corner ahead. Flip it, and a platform will lower ahead (with a former human or two). Ride the platform up to a "house", with numerous rooms filled with "furniture". Clear out the rooms - they contain minimal opposition (mostly former humans, and at worst, a Hell knight). Remember the location of the room with a double bed (southwest side of the house) - it contains a switch that will need to be flipped later.

Once the rooms are cleared out, head down the T-shaped stairs in the south and follow the red floor west into a "library". Kill the shotgun guy and Hell knight inside, then grab the blue key.

Yellow Key

Return to the room with a double bed, and notice a switch right next to the door. Flip the switch, and a concealed door in the middle of the T-shaped stairs will open. Run to the new alcove, which contains a teleporter (on Hurt me plenty and below, there is also a plasma gun that will come in handy). Step into the teleporter.

You are now in a stone hallway. Kill the chaingunner in front of you (if any). Equip your plasma gun, then follow the tunnel around, clearing out a revenant, followed by another revenant (on Hurt me plenty and below) or an arch-vile (Ultra-Violence and above) at the bend. Midway through this tunnel, a teleport trap will be activated. Monsters will teleport in front and behind you (as well as into the yellow key alcove), wedging you between:


 * Hey, not too rough and below: three shotgun guys and two lost souls;
 * Hurt me plenty: one shotgun guy, four lost souls and two Hell knights;
 * Ultra-Violence: seven lost souls, two Hell knights and one baron of Hell.

Due to the design of the trap, a shotgun guy (Hurt me plenty and below) or the baron of Hell (Ultra-Violence and above) will almost always teleport into the yellow key alcove, leaving you boxed in by a pair of shotgun guys (Hey, not too rough and below) or a pair of Hell knights (Hurt me plenty and above). Clear them out and continue forward.

The yellow key is in an alcove blocked by a blue bar. Open the blue bar and take out any monsters that teleported inside. Grab the yellow key from the back of the alcove, then backtrack to the teleporter.

Outside, Red Key and Exit

The exterior area is sparsely populated by imps, demons and arachnotrons. They shouldn't be too much of an issue. Proceed to the east of the courtyard, where there is a wooden structure with orange skull bars in the corners and a switch on top. Near it is a switch sticking out of the ground. This switch will lower part of the wooden structure - flip it, get on the wooden structure and ride it up to the switch on top. Flip this switch to raise steps in the northeast corner.

Proceed to the northeast corner and climb the steps. When you cross onto the green ground on top, immediately face backwards and equip the chaingun, as a teleport trap will activate and drop some shotgun guys and imps behind you. If you're counting kills, there are five (Hey, not too rough and below), nine (Hurt me plenty) or 12 (Ultra-Violence and above) monsters that will teleport in. Collect the ammo and flip the switch to raise stairs in the southwest corner.

Proceed to the southwest corner and go up the steps. The structure looks seemingly innocuous, but will open up without warning. To open up the structure, walk from the stairs towards the two bulk cells. Up to four mancubi will be revealed. You might want to get out of that area before you get boxed in by these large monsters. Once the area is clear, flip the switch hidden within the structure to lower a bar in the northwest.

Head to the northwest, where you can see a graveyard. Step up onto a brown path. If you stay on this brown path until you reach the yellow door ahead, you can stay safe. However, if you stray from the brown path, monsters will rise out of the graves, but you can get a rocket launcher and some ammo. It is strongly suggested to trigger this trap first, or you might find yourself in a tight squeeze when you face the monsters behind the yellow door at the end of the path. Whatever you do, head for the yellow door.

Open the yellow door. Kill the chaingunners, revenant or arch-vile ahead. Look for the switches in the far corners of the room, and flip one to activates its corresponding lift. Ride either lift down.

In this stone tunnel, you do not need to enter the room beyond the steel panels unless you want 100% kills, or wish to get the megaspheres. Instead, go east and kill the two imps (Hey, not too rough and below) or Hell knight (Hurt me plenty and above). At the end of this corridor, the red key is in an alcove guarded by a baron of Hell (Hey, not too rough and below), two Hell knights (Hurt me plenty) or two barons of Hell (Ultra-Violence and above). Keep them in the alcove by not lowering the wooden panel keeping them in, making their plasma easier to dodge.

Once they are dead, lower the wooden panel, but turn around, equip the plasma gun and walk backwards into the red key. This allows you to get ready for a trap that opens opposite the red key alcove, with two spectres (Hey, not too rough and below), two Hell knights (Hurt me plenty) or two barons of Hell (Ultra-Violence and above), before the monsters inside overwhelm you.

Leave the alcove by lowering the wooden barrier, then ride the lifts back up to the surface. Head to the southern end of the map and find the brick structure with a red bar. Open the red bar and flip the switch inside, which opens the gate next to it. Your final opposition is a Hell knight (Hey, not too rough and below), two Hell knights (Hurt me plenty) or two barons of Hell (Ultra-Violence and above), which will come from beyond the gate.

If the gate has closed, re-open the red bars and flip the switch inside to open it again. Following the brown path, walk past the perimeter brick walls to exit the level.

Other points of interest
The megaspheres in the dungeon at the very northwest of the map seem to be reachable on multiplayer mode only, but can be collected in single-player mode too. There are six skull switches, therefore abbreviated by S and numbered from (left) south to (right) north. On entering that dungeon you are facing the two central switches (S#3 and S#4). Each switch lowers a lift of the "stairs" with an item on it. Be fast, as the lifts stay lowered just for short while. Push S#3 (to lower the lift in front of S#6), S#4 and S#6 (from the lowered lift - simply push the wall below it to lower the lift in front of S#2). Run to the lowered lift in front of S#1 and step over on the lift in front of S#2. No need to hurry anymore, wait for the lift to raise. S#2 lowers the lift with the northern megasphere, so it is pretty useless for you. So instead step on the banister south of the lift you are on and walk over to the southern megasphere.

Do the same procedure again mirror-inverted to get the northern megasphere.

Official

 * 1) Inside the dungeon you start the level in, the southwestern cellar contains a lantern on a wall; shoot this wall to reveal a box of shotgun shells (sector 173).
 * 2) When the elevator west of the dungeon is lowered, the southeastern wall can be walked through, leading into a compartment (sector 309) containing a soul sphere.
 * 3) The sector containing the switch (sector 316) in secret #2 that lowers the elevator is also marked as secret. However, it is impossible to register due to being too small for the player to enter.
 * 4) Upon leaving the elevator, enter the marble room in the northeast of the house and press on the demonic face at the south. It will open a portion of the eastern wall (sector 253) to reveal a blur artifact.
 * 5) In the library where the blue keycard resides, press on the bookcase west of the couch. It will unveil a secret room (sector 113) behind the desk containing two chaingunners, (a backpack on easy and medium skill levels,) a shotgun, a chaingun and a super shotgun.
 * 6) After descending either elevator in the stone area following the yellow key door, the wall east of the eastern torch is covered in muck. Press on this wall and the platform (sector 233) between the elevators will lower, allowing the soul sphere resting upon it to be obtained.
 * 7) After descending either elevator in the stone area following the yellow key door, a portion of the northern wall is covered in muck. Press on this wall and it will lower to reveal a blue armor (sector 296).

Non-official

 * 1) The fireplace inside the house contains a berserk pack. However, the floor inside will heavily hurt you.
 * 2) At the main staircase the lowest sector of the eastern handrail is a lift that allows climbing onto the banisters. From there you can jump over to the western handrail at the top of which a wall to the southwest can be walked through, leading into an alcove containing a megasphere.

Bugs
Due to a secret being impossible to reach, you can only obtain 85% Secrets on this level.

Routes and tricks
The switch that raises the staircase in the northeast of the map can be flipped early when the elevator around it is lowered, as long as you are facing the linedef the switch is on and within activation range. Walk against the east or west sides of the platform the switch is on, and face the linedef before triggering it.

Although the intended method to obtain secret #6 is to lower the platform it is on by pressing a hidden switch, you can also take the elevators to either side of it, and strafejump onto the platform from there.

The megaspheres in the room west of the red keycard are meant to be obtained in cooperative multiplayer gameplay only, but it is possible to acquire them in single-player. To do so, flip the two front switches, press one of the first inner switches, and then run to the second platform lowered on the other side. Wait for it to raise, and then walk onto the outer edge. From there, you can walk onto the platform the megasphere rests on and obtain it. You can do so for both sides. However, because it takes up more time than is needed to finish the level, this is only used in episode and full-game runs, where it is used to obtain one megasphere in preparation for the next level.

Current Compet-n records
The Compet-n records for the map are:

The data was last verified in its entirety on July 4, 2020.

Current DSDA records
The records for the map at the Doom Speed Demo Archive are:

The data was last verified in its entirety on February 24, 2022.

Player spawns
This level contains six spawn points:
 * 1) facing west. (thing 95)
 * 2) facing south. (thing 96)
 * 3) facing south. (thing 97)
 * 4) facing west. (thing 135)
 * 5) facing south. (thing 136)
 * 6) facing north. (thing 179)

Things
This level contains the following numbers of things per skill level: