I have never had a first-night experience like this. I will not soon forget the sight of some musty jar of human fingers, bottled as if they were choice delicacies to eat, or a syphilitically-decayed nose in a display case.

I cannot explain why I entered into the spirit of things, turning interactive. I came upon a room supposed to resemble a Victorian opium den and inquired of the bow-tied attendant: "Do you have any opium or cocaine? My need is urgent." "Bold, aren't you?" he complained, waving me towards a scarlet-cushioned recess.

Parts of theatre-goers that are never reached let alone touched on a normal night at the theatre were fingered last night. I was caught in the midst of Punchdrunk's-The Masque of The Red Death, a highly successful attempt to plunge participating audiences into the horrors of Edgar Allan Poe's plague, ghost and murder-ridden stories.

Compulsorily dressed in silly face-masks, we were invited to prowl a creepy candle-lit BAC, from subterranean cellars - one equipped with an elderly coffin - to closetted rooms, each one memorably transformed with ancient bric-a-brac and furniture into a scenic correlative of some incident from the stories. Here were faded letters, stuffed foxes, French music hall entertainment in full flow and actors, directed by Felix Barrett and Maxine Doyle, enacting scenes and fragments from those Poe tales.

The musty air was full of baleful screams, portentous music, striking clocks, maidens writhing in pain and sinister 19th-century gentlemen prowling. Suddenly, I was snatched by a cloaked, bearded, cane-flashing young man, dragged into a small dark room, pinned against a wall. The door was locked. I feared for the remains of my virtue. "I know who you are," he snarled, placing his slightly handsome face too close to mine. Pressing his cane against my neck he rained down obscure abuse upon me.

The climactic, liberating finale snatched us from such flamboyant melodramatics to a masked ball where Death itself collapses. Young audiences adore these London Dungeon-style theatrics but after the similarlystyled Faust, the company seems caught in a brilliant Gothichorror rut.

Punchdrunk should use its rare, evocative gifts for some serious, epic business - Britain, say, on the verge of war in 1939 - rather than brilliantly indulging its love of the macabre.

• Booking to 12 January. Information: 020 7223 2223.