A PAIR of scientists will fire million-volt bolts of lightning at each other on stage next month in a theatrical show so dangerous that it requires £12 million in insurance cover.

Either Richard Wiseman, the psychologist, or Simon Singh, the physicist, broadcaster and author, will risk his life inside a coffin-shaped metal cage on each night of Theatre of Science, which opens on July 4 for nine performances at the Soho Theatre in London.

At the climax of the show, the audience will vote on which scientist they want to see restrained inside the cage, which will then be struck by at least a million volts of electricity — easily enough to kill a person.

But Professor Wiseman and Dr Singh should be perfectly safe: the device, known as a Faraday cage, after the 19th-century inventor who came up with the idea, is designed so that the current will pass around the body of anyone inside it. However, if either man were to stretch a finger outside the confines of the cage, he would be in mortal danger and the bolt would deliver a lethal shock in the same fashion as an electric chair. The restraints which will be on display are, therefore, used not only to add a Houdini-like thrill to the spectacle, but also to stop the scientists from harming themselves.

Professor Wiseman, of the University of Hertfordshire, had originally wanted to recruit a volunteer from the audience for the stunt but was refused permission by Westminster Council, the theatre managers and his insurers.

“I was barely halfway through the sentence when they started saying, ‘Don’t even think about it’,” he said. “So we decided that Simon and I would have to be the guineapigs instead.”

The electricity for the stunt will come from two large Tesla coils, a pair of transformers that slowly build up a charge before creating crackling bolts of lightning.

The coils will be used elsewhere in the show, but the performers have been banned from switching them on for more than 20 seconds because of the noise and light.

The audience and performers will be just beyond the maximum range that the bolts can reach — the precise details are not being released to add to the suspense — and earth wires will be placed on the ceiling to guard against an upward strike.

“Everybody will be outside the strike range — but not very far outside it,” Professor Wiseman said. “That’s why we have had to get £12 million insurance cover. God, I hope we don’t have to claim on it.”

The show is not suitable for those aged under 16 or for anyone using a pacemaker.

• Theatre of Science runs at the Soho Theatre on July 4-6, 11-14 and 18-19. Tickets are £12/£10 concessions, and are available on 0870 4296883 or www.sohotheatre.com

ELECTRIFYING PERFORMERS

• Humphry Davy: the scientist who invented the miner’s safety lamp also experimented publicly with nitrous oxide, better known as laughing gas, demonstrating its intoxicating effects

  Michael Faraday: Davy’s former assistant at the Royal Institution built the Faraday cage, coated with metal foil, and exposed it to bolts of electricity. He used instruments to show there was no excess charge inside the cage

  Harry Houdini: his most famous trick was the Chinese Water Torture Cell, in which he was suspended upside-down in a locked glass-and-steel cabinet full of water

  Walford Bodie: nicknamed the Electrical Wizard of the North, Bodie passed electricity through his body. He used only static electricity, which looked impressive but was harmless