The Cistern
THE CISTERN
Overview: The cistern was built when Aranda Markelhay raised her tower; if a city was to be built, it would need a more secure water supply in the case of a siege than the river. The cistern is now dry as the floodgates have been closed. The circulation system to keep the water from growing stagnant is still in working order, though the waterwheel which powered it (beneath the falls) has been destroyed.
A group of wererats, worshipping a horrid, demon-like creature they call the Rat God, have moved in here and made it their lair. They are smart enough not to plague the townspeople of Fallcrest, but will strike at merchants. They have filled the cistern with rats and have kidnapped a number of merchants as slaves to their Rat God.
The Rat God is an aberration from the Far Realm; it is sleeping, senseless, having crawled into this place after the Bloodspear War to feast on the remains of the dead left after the sacking of Fallcrest. A travelling arcanist discovered it here and placed magic wards to keep it from leaving if (and when!) it would awaken.
Entrances: There are a number of entrances to the cisterns:
1. Via the Markelhay Sepulchre. A stair descends to a secret door. No one is aware of the existence of this door.
2. Via a well in Moonstone Keep. The well has been capped as the cisterns are now dry.
3. Via a well in the Tombwood. This well has been overgrown but is not capped.
4. Via a passage through the crypts under the Tombwood.
5. Via a passage from the catacombs in the Moonstone Caverns.
1. Cistern (XP 150)
A vast chamber (100x100) that echoes with the squeal of thousands of rats. The ceiling is vaulted and leads up into darkness. Pillars support the weight of the earth above.
There is a 20' deep pit in the middle of the room, measuring some 40x40 feet in area. It would be empty save the thousands of rats who climb over one another here. Two 5' wide tunnels lead out of the pit, one heading north and the other south. Rats are climbing into and out of these tunnels.
4 doors line the walls. Most are made of wood and warped or decaying; one is made of stone and is closed fast.
Dim lanterns line the walls and give off a faint light.
DM's Notes: A single wererat rests here in the shadows, on guard. There is a 50% chance that he is sleeping, giving the PCs automatic surprise, though he will wake shortly (in 1d4 rounds from the PC's arrival) as the rat's squeals grow in intensity. If he is not sleeping, PCs who have low-light vision spot a man is guarding the area and have them make a check; the DC is 14. If the PCs succeed, they spot the wererat before he spots them and may act as they wish with surprise. His suspicions will become aroused shortly, however, due to the strange activity of the rats; unless the PCs do something to calm the rats, the PC with the lowest Stealth modifier must make a check against DC 19 (though other PCs may Aid). Succeed or fail, they will see him, and he will attempt to flee into the wererat lounge (area 6) to warn his allies.
(Optional) Assassinating the guard: As the rats serve as a alarm of sorts for the guard, it is unlikely that PCs will be able to slip past him. However, a single character trained in stealth may be able to do it. By slipping from pillar to pillar a character can maintain stealth, although at a -5 penalty. (Do not call for rolls each round; only one is needed, otherwise you might as well state the character fails automatically!) Once in range of the wererat, maintaining Stealth indicates the PC will have surprise and can make an attack.
This attack is unlikely to kill any but a helpless guard or minion. The goal, then, is to make an attack to make sure the target cannot cry out for help. Make an attack as a standard action, rolling Str or Dex vs. Fort; on a hit, the target cannot shout he target cannot shout, yell, or talk normally, though he can still whisper (save ends). Combat can then proceed, though the guard will attempt to flee (best to grab him). These sorts of combats are best considered to be done in near total silence (DC 20 Perception to hear).
The cistern is empty of water, the floodgates closed, but it is filled with rats. Anyone who does not have immunity to filth fever who enters or begins their turn in the cistern takes 5 points of damage and suffers an attack: +7 vs. Fortitude, on a hit the character contracts filth fever. Although it is 20' deep, treat falling distance as half that due to the soft cushion of rats the character will land upon. See the control room (area 2.) for details on what occurs when the floodgates are opened.
Every 20' there is a line of squares (1x4) that is in total darkness. Characters with low-light vision can penetrate the gloom. The wererat guard hides in one of these squares
There is a well that draws water from the cistern when it is full (though it is covered at the moment); PCs can notice this if they have low-light vision or darkvision and succeed at a DC 18 Perception check.
2. Control Room.
The stone door to this room is locked (DC 20). When opened, the room seems to gasp as stale air exits; it has not been opened for nearly a hundred years. Within the stone room is a large wheel, a pair of levers, one up and one down, and two gauges. Dwarven writing has been carved into the wall above each control. Both gauges read 0.
A corridor in the western wall leads into darkness.
DM's notes: If a character can read dwarven, they can make out the following: "Main Floodgate" over the wheel, "Cistern" over the left lever, "Moonstone Well" over the right lever, and "Water Level" and "Hammers" over the gauges. ("Hammers" is a dwarven measure of force equal to the force required to lift a warhammer 3 feet (basically 1 newton); it measures the amount of energy the waterwheel produced. The waterwheel which once stood behind the falls has been destroyed.)
The wheel opens the main floodgate. If turned, it will make a great creaking noise unless oiled, and will alert anyone in the cistern (area 1.) or the wererat lounge (area 6.). Once opened, the sewers will flood with water and can once again be used by Fallcrest (instead of dumping waste directly into the river, it is taken downstream a few miles). Reward characters who open the main floodgate with a level 1 minor quest.
The levers open the floodgates; the left one opens the floodgates that sends water into the main area, and the right opens the floodgate that leads to the small cistern that feeds the well under Moonstone Keep. If the left floodgate is opened, a roaring sound can be heard coming from the western tunnel in the cistern (area 1.); in 5 rounds, a gust of water will pour from it. Any creatures within 5 squares of the western tunnel are subject to an attack: +10 vs. Fortitude, 3d8+5 damage and knocked prone. This will clear out the rats in the cistern within 2 rounds as they flee into other areas, creating difficult terrain in the rest of the cistern until the end of any encounter. Creatures within this difficult terrain are subject to an attack: +7 vs. Fortitude, 4 damage. If any damage is dealt via an area affect (such as a scorching burst or flask of oil, but not blinding barrage), those squares are cleared of rats until the end of the character's next turn. If this occurs outside of an encounter, each character must make a DC 19 check or lose a healing surge.
In a short time, the cistern will fill; if both levers are opened, the Moonstone Keep cistern will fill as well. Fresh water may be drawn from the wells. In a week, however, the still water will foul and those who drink it are subject to an attack: +3 vs. Fortitude, on a hit contract filth fever (dysentery/flux).
3. Moonstone Keep Cistern (XP 300)
The northern tunnel leads into a vaulted chamber, 15x15. A small pit, 20' deep and 10'x10' in area, dominates the room. The pit is lined with a yellow sludge. There is a shaft in the ceiling.
DM's Notes: The yellow sludge is actually an ochre jelly. The wererats fought it and were unable to defeat it but pushed it into this area. A Dungeoneering check (DC 15) will indicate that PCs know what this is (though let the players metagame). It will lie dormant and attack once all PCs enter its space, or attack if assaulted. The ochre jelly suffers no penalty for having other creatures in its space as it flows around other creatures. (If using this modified rule, add an extra 100 XP to the encounter.)
Treasure: The chain that once held the bucket to feed the well still lies here; it is made of sterling silver and worth 100gp.
4. Storeroom.
This room (30x30) is full of a variety of goods - grain, meal, chickens, spices, tools, luxuries, etc. It appears that some of the banditry attributed to the Raven Roosters is misplaced. A set of stairs in the north wall leads up. There is a simple wooden door, recently repaired, in the western wall.
DM's Notes: This room is where the wererats keep their ill-gotten gains. There is a total of 470gp here - though 200gp of that is in trade goods which cannot easily be taken. If the PCs deliver this to market and sell it, reward them with a level 1 minor quest. The other 270gp is in magical reagents - 30gp of mystic salves, 100gp of alchemical reagents, 120gp of rare herbs, and 40gp of sanctified incense.
Those who search this room must succeed at a DC 19 Stealth check or they will alert the wererat guard in area 1.
The stairs lead to the tombwood crypts; the door leads to area 1.
5. Hightown Well Shaft (XP 350)
This shaft leads to the covered well just north of the Kamroth Estate, in the Tombwood.
DM's Notes: 2 Cavern Chokers lurk here, chased out of the catacombs, feeding off the vermin in the sewers. They have since had to be more cautious with the arrival of the wererats some few months ago.
If PCs climb the tunnel, they will come under attack. Likewise, if there is a battle in the cisterns, the cavern chokers will hear it and investigate; once the battle turns, the chokers will descend and attack. During the battle, anyone who calls for and makes a DC 20 Perception check will notice the chokers lurking there. The chokers relish the idea of gaining some treasure that isn't rat bone necklaces.
6. Wererat Lounge (XP 1000)
The door to this room is stuck (requires a DC 11 check to open; if Thievery is used, surprise is possible, otherwise the wererats will be aware of the PCs and gain a +5 bonus to initiative). This room (40x40) has two tables and a small fireplace. A roasted pig is on a spit over the fire. 5 wererats - one of exceptional size, with spiked steel armour over its tail - are lounging here. A keg of beer stands next to the fire. Three doors are here - one leading to the cistern, one on the north wall, and another on the west.
DM's Notes: Pushing someone into the fire will deal low limited damage based on the character's level (as those who are higher level push with more force!). The pig, if it takes any damage (such as from an area attack), bursts into pieces creating concealment in a burst 1 area for one round. If any large amount of liquid (such as the keg) is placed onto the fire, hot steam will burst forth, dealing 5 damage in a burst 1 area and creating concealment for one round. If the keg is put there, it will take 1 round before it explodes.
If attacked, one of the wererats will attempt to move into the sauna (area 7.) and the wererat warren (area 8.) to raise the alarm.
Wererat Killer: lvl 5 elite brute XP 400
init +6; per +4 (low-light)
AP 1; SV +2
HP 150/75; AC 17, F 19, R 20, W 17
regen 5 (silver)

cleaver +8 vs AC; 2d8+4 damage

bite; minor; requires CA; +6 vs. F; 1d6+4 and ongoing 5 (sv)

rage; when first bloodied; immediate reaction; close burst 1; cleaver attack against all enemies in range

spiked tail whip; immediate interrupt; when flanked; +6 vs. R; 1d10+4 and prone
S +4 C +4 D +6 I +1 W +4 C +1
7. Dwarf Sauna/Bathhouse (XP 875)
This 20x100 area is warm and the air is humid. The walls and floor are made from white tiles. Red-hot stones pulse with magical heat, covered by metal grates in sunken area in the middle of the room.
DM's Notes: This area is dimly lit. A lone wererat takes care of his 3 guard drakes and 2 spitting drakes in this room. The drakes are sleeping over the grates.
The stones that produce the heat and only light are magical; their heat can be raised or lowered by someone who speaks the correct incantation (Arcana DC 18; a Dwarf character can substitute a History check with a -2 penalty). The grates can be easily removed. If water is poured on the heating stones, a heavy burst of steam is created (concealment in a burst 1 area). If the grate is opened, any character who enters or begins his turn on that square takes 5 points of fire damage. If the heat is turned off, these effects do not occur.
Treasure: One of the drakes has a gem-studded collar worth 140gp.
Wererat Caretaker: lvl 5 controller
init +6; per +10 (low-light)
HP 63/31; AC 19, F 17, R 18, W 17
regen 5 (silver)

short sword +10 vs. AC; 1d6+4.

whip; ranged 5; +9 vs. R; 1d10+4, prone.

whip disarm; minor; encounter; +9 vs. R; one held item is disarmed and ends up within 5 squares.
sic 'em; minor; encounter; ally within 5 makes basic or charge attack with +2 to atk.
Stealth +11, Nature +10
S +3 C +4 D +6 I +2 W +5 C +1
8, Wererat Warren (XP 725)
This 25x30 area stinks of filth and decay. Pallid straw mats line the floor. A number of bags are scattered about the room. A fire burns low in a brazier in the middle of the room. A 10x15 area in the south-western corner is curtained off, and a candle flickers from the other side.
DM's Notes: This is where the wererats sleep. A dark creeper emissary from Raven Roost is meeting with the warren king, attempting to cow the warren king into paying a fee for working this turf. They are not making much headway. The warren king will not let the dark creeper leave with his life; he will be sacrificed to the Rat God (see area 9.).
A single wererat bodyguard (as wererat but with fighter's mark and +2 bonus to AC to adj allies) is in the room, ready to respond to any treachery from the dark creeper. This wererat is deaf.
The brazier can be used to light the mats on fire; this will create a thick, nauseating black smoke to rise, granting total concealment in a burst 1 area. Any character who enters or begins his turn in the smoke is subject to an attack: +7 vs. F; -2 to atk (sv). Wererats are immune (comfortably living in their own filth).
Treasure: The dark creeper has a silvered dagger worth 75 gp.
Warren King: lvl 5 elite controller (leader) XP 400
init +6; per +9 (low-light)
HP 126/63; AC 21, F 17, R 20, W 19
regen 5 (silver)
AP 1; SV +2

filthy short sword +9 vs. F; 1d6+4, ongoing 2 (sv) and filth fever.

flying rats; ranged 5; +9 vs. R; 1d4+4, -2 to atks (sv). The warren king throws a hungry rat at the target.

tail trip; reach 2; +9 vs. R; 1d6+4 damage and the target is knocked prone.

create rat king; only in cistern full of rats; creates large rat king in the cistern and the rat king attacks. As a move action, move the rat king up to 6 squares; +9 vs. R; 2d8+6 damage and the rat king grabs the target; sustain minor: a target grabbed by the rat king takes 1d8+6 damage. As a standard action, the warren king can make another attack but it must release a target it has grabbed.

release rat swarm; encounter; close burst 3; targets enemies; +9 vs. F; 1d8+6, ongoing 5 (sv) and difficult terrain (not to wererats). The warren king can no longer make flying rat attacks.
Stealth +11, Streetwise +9, Thievery +11
S +3 C +3 D +6 I +6 W +4 C +4
equipment: filthy short sword, bag of rats
9. Lair of the Rat God (XP 1000+)
The entrance to this room is marked with ancient runes. At the far side of the circle, flies buzz angrily against an unseen barrier. A mass of red-eyed maggots has created a carpet one-foot deep on the floor, squishing up against the magical ward.
This large (35x55) vaulted chamber stinks worse than an outhouse in the middle of summer. In the dark, a horrid wheezing sound comes in uneven intervals.
DM's Notes: A far-realm entity known only as the Rat God lives in this squalid chamber. It is not a rat nor a god but the wererats worship it as such, giving it sacrifices (which it slowly consumes through its maggot offspring, feeding off the pain). The rat god sleeps but will awaken if attacked.
5 creatures have been sacrificed to the rat god and have died, becoming slithering spawn. Treat 2 as fire bats (remove ongoing fire damage, increase damage to 1d10+4) - a cross between a man and a fly; 1 as a vine horror - a mass of maggots in humanoid form; and 1 as a slaad tadpole, a large flesh-devouring worm.
10 squares are covered in maggots; treat as a treacherous ice sheet.
Two slaves, one a halfling merchant, the other a human, cower in the corner. They are slowly being eaten alive from the inside out by the flies and maggots that fill the room. If left to die, they will become slithering spawn. If saved, grant the PCs a level 5 minor quest.
Treat the rat god as an adult green dragon with the proper reskinning (no fly speed, flyby attack = slither, breath = maggot explosion, etc.).
Treasure: The wererats have thrown five 100gp gems into this room as tribute to their god.