The Tides of Saint-Brendan

Saint-Brendan was once a prosperous town of coopers, whose barrels sailed on every sea. Today it is a half-dead place, drowned in fog, where the air smells of salt and something older. Its last inhabitants have skin too smooth and eyes set too wide. People blame the inbreeding of an isolated town. They are wrong.

The hook

Each of the investigators received the same letter from an old mutual friend, Jonas Whitlock, a scholar who had settled in Saint-Brendan to write a book. There he uncovered something he dares not name, and begs them to join him before the new moon. When the group arrives, Jonas already lies at the centre of the municipal library, in the middle of a circle traced in salt and blood.

What the town hides

"The decline of trade is no accident. Beneath the docks and beneath the old families lies a very ancient arrangement."

A hundred and fifty years ago, to escape famine, the founding families sealed a pact with the dwellers of the abyss: prosperity in exchange for a blood tribute, paid every thirteen years. But one faction of the cult, the Assembly of the Ebb, is no longer content to pay. It means to wake He-Who-Sleeps-Beneath-the-Swell, convinced he will make the seas fruitful again. It is wrong. His waking will swallow Saint-Brendan, and far more besides.

The five acts

• Act I, The Letter: arrival in a hostile town, unease, things left unsaid.
• Act II, The Library: the grisly discovery, the investigation, the temple beneath the temple, and the trap closing shut.
• Act III, The Siege: surrounded by the cult, survival and an unexpected ally.
• Act IV, Beneath the Docks: the descent into the brine chambers, the cocoons, the abyssal sentinels.
• Act V, The Rising Tide: the ritual, the final dilemma, and what rises from the bay.

Advice for the game master

Let the dread build slowly: Act I is nothing but unease and details that ring wrong, and the first true monster appears only in Act III. Treat Sanity as a narrative resource, not a mere number: describe the trembling hands, the breaking voice. And remember that the final dilemma has no right answer: breaking the pact saves the world but dooms the town, interrupting it saves the town but only postpones the horror. Let the weight of that choice rest on the players.