Like all of Artangel's projects, Night Haunts began with a series of conversations between the project creator (in this case, Sandhu); the group's codirectors, James Lingwood and Michael Morris; and Cathy Haynes, head of Artangel's Nights of London program. "Artangel's basic remit is to find ways of encouraging some of the most brilliant and original artists working today to kind of step out and into different kinds of public spotlights and realize their dream project," says Lingwood. "They are not projects that sit easily within a more conventional gallery space or theater space. Artangel's place in London is to try and offer artists with very distinctive voices a very distinctive place for that work to be made."

That philosophy has yielded some marvelous results. Since 1991, four artists who worked on Artangel projects have gone on to win the Turner Prize, an annual award given to a British visual artist under the age of 50 and one of the United Kingdom's most-publicized prizes. Artangel worked with filmmaker Matthew Barney on the first of the Cremaster films; Jeremy Deller on The Battle of Orgreave, a critically acclaimed remake of a famous miners' strike; and Rachel Whiteread on House, a public sculpture of a Victorian terraced house in London's East End.

"Artangel crept up on us all like a thief in the night. Suddenly, they were robbing us of all our old and familiar ideas about what art in public spaces could be," Cook says. "I don't think it's an exaggeration to say that a project like Francis Alÿs's Seven Walks [which explored the everyday rituals and habits of the metropolis] last year helps to change the way you feel London. In some ways, it also makes you remap the city, compelling you to look again at familiar spaces and leading you off in all manner of undiscovered corners."