A chapel, and older than the maze around it: four columns, a stone altar, and along the walls a carved relief of a wave that runs the whole length of the room and never breaks. The floor is wet. So are the columns, to a line about level with your chest, and above that line the stone is dry and salt-white.
A bronze bell hangs in a cage above the altar. As you watch, with nobody near it, it strikes once. Somewhere under the floor, water starts to move.
DM summary. A tidal chapel on a strict five-round cycle, with a bell that counts the cycle out loud. The drowned in here fight better as the water rises, so the room is a race against a clock the party can hear.
Terrain & Features
Battle map: The Pillared Sanctum — page 36, 55 × 75 ft (one half of The Hall and the Sanctum)
The pillared sanctum is the chapel: the altar is printed, the four nearest columns are the rung-fitted ones. Shade the water line as it climbs — dry-erase was made for a rising tide — and chalk the bell cage 15 ft over the altar.
- Dimensions. 50 ft × 40 ft, ceiling 22 ft. The party enters at the east end, three steps down — which means the water reaches them last and leaves them first.
- Light. Dim green from two lamps of some sea-oil in wall sconces above the tide line, which is the only reason the party can see anything at high water.
- The four columns. 3 ft across, salt-eaten, each with iron rungs set into it by somebody practical. Climbing one is Athletics DC 12, and the top of the capital is above the high-water line.
- The altar. A stone box 6 ft by 3 ft in the middle of the floor, standing 4 ft high. At high water it is submerged. Under its west face is an offering slot — see Loot.
- The bell cage. A bronze bell on an iron frame 15 ft above the altar, reached by the column rungs and a 10-ft crawl along the frame (Acrobatics DC 13). Six people fit on the frame, badly.
- The sluice. A barred grate in the north-west floor corner, 3 ft square, through which the water comes and goes. The sluice gate behind it is worked by a bronze screw beside the grate.
- The wave relief. Decoration, and a tide gauge: the carved wave's crest is cut at exactly the height the water reaches. Perception DC 12 to notice that the carving and the salt line agree, which tells the party how bad this gets.
Encounter
Five bodies that want the water to keep rising, and it will.
| Count | Creature | XP each |
|---|---|---|
| 4 | Drowned Hoplite | 700 |
| 1 | Siren of the Sunken Court | 1,800 |
Base 4,600 XP; ×2 for five bodies = 9,200 adjusted, against the APL 9 Hard budget of 9,600. The tide is not in that number. A party still fighting at the five-strike is fighting a Deadly encounter and should be told so by the bell.
Round 1. The drowned are lying on the floor, waterlogged and slack, and look like four more drowned men in a chapel full of them. They stand at the two strike — knee depth, when they stop being slow. The Siren is already on the bell frame, out of the water, and she starts singing at the top of round 1 whether anyone has noticed her or not.
Tactics. Drowned Hoplites are slow on land and fast in water: at ankle depth they are half speed and easy; from waist depth up they are the fastest things in the room and they grapple to drag targets to the flooded west end. The Siren's song pulls one target per round toward the deepest water — she never enters it herself and she will not come off the frame. Kill or silence the Siren and the encounter loses its direction; the drowned will keep grappling but they have no plan to serve.
Nothing follows the party out of the chapel; the drowned cannot climb the three steps at the east end at any water level.
Bypass Options
Fifty feet at ankle depth, from the east steps to the west door, with the bell telling you exactly how long you have.
- The window: two rounds, rounds 1 and 2 of the cycle. A party moving at full speed makes it if they do not stop, and Athletics or Acrobatics DC 12 covers anyone who has to get past the altar at speed.
- Success: the party is at the west door before the drowned finish standing up. No initiative, or one round of it and then a closed door behind them.
- One failure: somebody goes down in the knee-deep water and loses their movement. The party can leave them, come back for them, or hold the door — a genuinely good three-second decision.
- Two failures: the party is mid-room at the three strike with four drowned standing. That is the fight, and it is now happening in waist-deep water.
- The cost of trying and stopping: if the party turns back to the east steps they can withdraw to the corridor at no cost but a wandering-threat roll. The chapel keeps its tide and its offerings.
The frame is above the high-water line and the drowned cannot climb.
- Getting up: Athletics DC 12 on the column rungs plus Acrobatics DC 13 along the frame. Six people fit.
- What it costs: the Siren is up there. She is one creature, on a narrow iron frame, against a whole party — this is the fight the party wants, and it is worth 1,800 XP rather than 9,200.
- Waiting it out: the tide cycles endlessly, so waiting gains nothing on its own. What the frame buys is the bell rope shaft (exit C) and a dry, safe vantage from which to work out that the sluice exists.
- Failure on the crawl: a fall into whatever depth the water is at. At the four or five strike that is a fall into four drowned hoplites, and it is the worst outcome available in this room. Do not let a player attempt the crawl at high water without saying so first.
Traps / Puzzles / Checks
The tide, and the bell that counts it. The cycle is five rounds long, it runs continuously from the moment the party enters, and the bell strikes once at the top of each round — so the table always knows what round of the cycle it is without asking.
| Round | Bell | Water | Effect |
|---|---|---|---|
| 1 | One strike | Draining, ankle deep | No effect. This is the window |
| 2 | Two strikes | Knee deep | Difficult terrain for Medium creatures |
| 3 | Three strikes | Waist deep | Difficult terrain; ranged attacks into or out of the water at disadvantage |
| 4 | Four strikes | Chest deep | Movement is a swim (Athletics DC 12 to move at half speed); Small creatures swim or drown |
| 5 | Five strikes | Full, ceiling to floor at the west end, 3 ft of air at the east | Hold your breath. Anyone who cannot must make a Constitution save DC 13 each round or begin suffocating |
Then it drains, and the bell strikes once, and it starts again. It does not stop. Nothing in this room turns off the tide except the sluice.
- Detect: the salt line and the wave carving, Perception DC 12 or free on a second look. A party knows how high this goes before it gets there. That is the telegraph, and it is not optional.
- Disarm (the sluice screw): Thieves' Tools DC 16, or Athletics DC 17 on the screw with a bar. Two rounds of work, and it must be done at knee depth or lower — which means round 1 or 2, which means the party has to decide in the first twelve seconds of the room.
- On a success: the sluice jams open and the chapel drains permanently. The cycle stops at ankle depth. The room becomes a straightforward fight on dry stone, and the drowned lose most of what makes them dangerous.
- On a failure: the screw shears and the sluice jams shut at the current level. The water stops cycling and simply stays where it is — for the rest of the session, this chapel is chest deep. Say it plainly; it is a real cost, and it is the reason to send your best hand.
- Solved state: either the sluice is open and the room is drained, or the party crossed on the clock. Both are wins. Only one of them is dry.
Exits
One roll on the loot table, from the offering slot under the altar's west face.
The condition is the tide: the slot is only reachable at ankle or knee depth (the one or two strike), and it takes a full round of a character's action to work the offerings out with a hand or a knife. That means somebody spends the crossing window on treasure instead of distance, which is the trade the room is built to offer.
The bell is bronze, valuable, and weighs six hundred pounds. Let a player try.
Scaling — APL 6 / 12 / 15
| APL | Adjustment |
|---|---|
| 6 | Three drowned, no Siren. The cycle is six rounds and stops at chest depth — nobody drowns at APL 6 in this room. DCs −2 |
| 9 | As written |
| 12 | Six drowned and a Scyllan Horror in the flooded west end that only fights from waist depth up. Cycle is four rounds. DCs +1 |
| 15 | Six drowned, a Scyllan Horror, and the Siren sings from the shaft above the bell where she cannot be reached at all. Cycle is four rounds and the full-water round lasts two. DCs +3 |
- Pacing: twenty minutes. When you are behind schedule, run the cycle once: describe the bell, give the party the two-round window, and let the crossing be one group check. Do not run three full cycles — the room makes its point the first time.
- Strike the bell out loud at your table. Say "one," "two," "three" at the top of every round, every time. The whole design lives on the players knowing exactly how much time they have, and a DM who tracks the tide silently has thrown the room away.
- The sluice is the clever answer and it should be rewarded. A party that sends its rogue to the corner in round 1 while everyone else holds the door has played this room correctly and deserves the dry version of it.
- Clue drip. Two hooks: the offerings in the altar slot are sea-things — coral, a shark's tooth, a ship's nail — and one of them is a house key, which is a strange thing to promise a sea god (X16, X11). And the wave relief runs west and does not stop at the wall, which means the carving continues into rock that has water behind it (X16, X11).
- Table safety. This room can put a character underwater in the dark, and
drowningis flagged for that reason. Say the word "tide" before you say the word "ceiling," give the east end its 3 ft of air at every water level, and if anyone at your table would rather not, cap the cycle at chest depth and lose nothing but a round of tension. - Callback. Deep Water Kin (W14) always fight from the water and always try to move you into it. A party that has met them in a flooded courtyard or a half-sunk nave should recognise the pattern here immediately — and the recognisable counter-play, staying dry and high, is exactly what the columns and the frame are for.
Creature Cards
Both belong to Deep Water Kin (W14) and recur across the deck, so the numbers live in the bestiary. The tactics above are this room's and stay here.
Shared across rooms, so the full cards live in the bestiary: Drowned Hoplite, Siren of the Sunken Court. Every mention above opens the numbers here on this page.