Here is a prologue that sets the mood, establishes the atmosphere, and seamlessly leads into the opening line of your story (filtering out the ad text embedded in your input):

The quiet dignity of Saint Jude’s Chapel had always felt like a shield against the dark, but tonight, the ancient stone walls offered no sanctuary. What had begun as a somber gathering to lay a memory to rest quickly twisted into a nightmare. A low, rhythmic tremor shook the floorboards, cutting through the weeping of the mourners and rattling the stained glass in its leaden frames.

The air grew frigid, heavy with the suffocating stench of freshly turned earth and decaying pine. Then, with a deafening screech of rending metal, the central marble aisle gave way, opening a jagged maw into the black void beneath the foundation. Panic erupted as the crowd scrambled for the exits, their screams echoing off the vaulted ceilings. Silas and I pressed forward through the chaos, desperate to see what had torn through the floorboards.

Before I could even process the sea of terrified eyes blinking up at us from the pitch-black abyss beneath the grating, a heavy iron shackle wrapped around my ankle with bone-crushing force.