(you'll need to click to embiggen)
Map by Lum at Built By Gods Long Forgotten ; whom I hope will forgive me for mutilating it
The area addressed is the NEW GATEHOUSE, which is the lower-right component of the castle.
1. Empty guard-tower. Arrow-loops look out at THE GREAT BRIDGE, where numerous Morths patrol. A spiral staircase here leads to THE SALLY-GATE ROUTE.
2. Vault. Decayed and partially-mummified corpses are strewn about, none with any items of value. Broken barrels, remnants of fire; one wall is partially collapsed near the ceiling. A Morth here is trapped beneath a pile of rubble and futilely clawing at the air. Arrow-loop looks out at THE BATTLE-TOWER; ragged shapes can be seen patrolling back and forth.
3. Heavy oak door requires Str check to open. Inside is dusty-but-mostly-intact Chapel of Kos. Pervasive sense of peace. When oak door is shut, all noise & light from outside is cut out. No Morths may enter this area. Gold trappings worth 1,000 Lunars are present, but stealing them will negate the sense of peace, allow Morths to enter and incur -1d100 Favor with Kos.
Secret Door (DC 15, unlocked) in South-East corner disguised as part of a fresco leads to AREA 5.
4. Grand Courtyard. 1d10 Morths are milling about pointlessly at any given time, amidst scattered desiccated corpses being pecked by ravens.
A badly deteriorated corpse is draped across the lip of the well on the East side of the courtyard, with one arm dangling into the shaft and seemingly pointing downwards. At the bottom, a dull glint can be seen.
This is a golden cross of Io. It adds +1 to attempts to Turn Undead.
5. New Gatehouse, West Tower. 3 Soldier-Morths with crossbows are stationed here, staring vacantly out at the Great Bridge. These Morths will be replaced with others from within the castle if destroyed. A legless Morth wearing rent chain mail and the heraldry of a Red Knight is crawling around and moaning. He will not be replaced if killed. Wall-racks hold 62 crossbow bolts in quivers.
Secret Door is visible in West wall; nearby torch sconce must be pulled to open it. Leads to Area 3.
6. New Gatehouse, East Tower. The door to this room is shattered. A blood trail leads away from it to AREA 8, and several Morth-corpses are nearby. 2 Soldier-Morths with crossbows are stationed here, staring out at the Great Bridge. These Morths will be replaced with others from within the castle if destroyed. The mangled corpses of two Red Knights are laid about like so much firewood. Their armor and weapons are in poor condition. Wall-racks hold 2 crossbows, 20 bolts and 3 long spears.
7. Barracks. Door hangs on rusted hinges. No windows or light. Tumbled, decaying beds, scattered furniture and linens. Searching takes 3 turns and turns up a chunk of heaterstone and 36 lunars in an overturned chest.
8. Common room. Door is hanging open. No windows or light. Rotten food still sits on tables. Blood trail continues from AREA 6 and proceeds through the room to the door to AREA 9. Faint scratching sounds can be heard from the other side of the door.
9. Guarderobe. Arrow slits look out on a steep defile leading down to the RIVER KOS hundreds of feet below. A particularly hideous Soldier-Morth (staring eyes, blood-covered face, pallid flesh) wearing the garb of a Red Knight is trapped within, producing the scratching noises as he claws at the door. His armor is usable; his sword lies forgotten in the small chamber (he attacks with his fingernails and teeth)
10. Storerooms and dormitory. Rotten horse corpse and a corpse lying in a bed with a sheet draped over it.
11. The Great Stable. Dark; empty stalls. The bones of the King’s steeds have collected to form a terrible entity known as a FARROPE, which will attack if anyone living enters more than 10 feet into the room. Otherwise empty.
12. The College. A short balustrade leads to an elegant and expansive columnade, inhabited by The SENESCHAL.
Attacks: Sword +3, Riding Whip +2 - 10 ft. range
Damage: 1d8+3, 1d6+2
The Seneschal wields his ceremonial badges of office as weapons. He wears a helm depicting a loyal hound, and can be observed constantly snuffling and sniffing the air. He is blind and deaf, and able to discern his surrounding only by smell. He can detect living beings by smell up to a distance of 100 feet, and discern their precise location if they are within 50 feet. If the PCs are able to disguise themselves as Morths somehow, such as by dressing in their rags or rubbing themselves with rotten flesh, he will not be able to detect them and can easily be avoided or destroyed. The Seneschal moves with incredible alacrity, and can traverse the entirety of the NEW GATEHOUSE in a single turn. He will pursue any interlopers as far as the OLD GATEHOUSE if disturbed, but is unable to enter AREA 3.
Destroying the Seneschal will prevent the Morths in the NEW GATEHOUSE (Areas 5 & 6) and on the GREAT BRIDGE ROUTE from being reinforced or replaced.
A giant tome of the history of Kos, largely intact, rests on a stand behind the Seneschal. This item is worth 100 Lunars to the right collector.
13. Old Hall. Dark. Moth-eaten tapestries, giant oak trestle tables, symbols of Kos (trident, grain sheaf, and crown) on the wall behind central table. Collapsed wrought-iron chandelier in the center of room. 35% chance of 1d6 Morths bringing a corpse or two to AREA 18.
14. Pantry. Racks of moldy bread and associated serving utensils. Corpse dressed in an apron lies face-down on the floor, but will stir to life as a Morth if disturbed (ie, by searching the room).
15. Buttery. Casks of old beer, several hundred candles. In a cobwebbed corner, one small cask of 400-year-old fig brandy resides. This has become so potent over the years that consuming it will provoke visions. Worth 250 Lunars.
16. Larder. Only accessible through AREA 18. Stacked with moldering corpses like cordwood.
17. Access hallway to Areas 13 - 18. 35% chance of 1d6 Morths bringing a corpse or two to AREA 18.
18. Kitchen. A stench is detectable from outside of rotting flesh and smoke.
The kitchen is occupied by the CHEF, mindlessly hacking corpses into cuts, then tossing them aside to rot in an enormous, unthinkably gruesome pile of slimily-decaying human flesh.
Attack: Cleaver +3
The Chef is intensely corpulent, sighing with confined corpse-gas and writhing with maggots. All attacks, checks and saving throws in the Kitchen or Larder are made at -2.
He is assisted by three other, standard Morths clad in aprons and servant's garb who will pursue outside the area (the Chef will not).
The room is intensely hot due to a blazing fire over which a human corpse is slowly revolving, and another firepit above which a huge cauldron of foul stew is boiling at all times. Anyone forced into either fire will be dealt 2d4 fire damage. The cauldron could also be tipped over, dealing 1d10 points of scalding damage to anyone underneath it.
Destroying the Chef will negate the chances of encountering Morths in Areas 13 - 18.
19. The Overlook. This wide expanse rises to the North, with a dais that overlooks both AREA 4 and AREA 12. A Mage-Morth is found here, guarded by two Soldier-Morths wielding spears.
A door in the west wall leads to a series of scaffoldings which allow access to THE BATTLE-TOWER. A large double-door (elaborately carved with dolphins and nautili) in the rear of the dais leads to THE CENTRAL TOWER.
20. Guard Tower. Empty.
21. College Gallery. Windows here overlook the SENESCHAL in Area 12, allowing him to be easily dispatched with arrows or spells - he will be unable to smell them.