A library is not generally considered an agent of chaos.

But that is perhaps its most important function. Utilizing an orderly Dewey-decimaled army of books, the library is the most disruptive of institutions, turning aside cherished beliefs, casual wants, and vague desires, and swapping in -- who knows what?

You put a group of wandering people into a library and you never can tell what they're going to come up with.

It is this cluster of contradictory and chance ideas that New Paradise Labs plays with during its path-breaking performance of Gumshoe, an interactive, wholly Free Library-centric performance that takes small audience groups sleuthing throughout the 90-year-old Central Library building on Logan Square.

From the Rare Book Department on the third floor to the musty and mysterious basement storage rooms and offices, New Paradise's groups of audience detectives follow a trail of hints and clues to decipher a mystery that seems just out of reach.

The hero, not surprisingly, is the library itself, the summation of all it contains, the building that houses all other ideas of buildings. As the great Argentine writer Jorge Luis Borges put it, the library is a universe by another name.

The occasion for the performance is the Free Library's pair of exhibitions "We the Detectives," which highlights (in the Rare Book Department) Edgar Allan Poe's original manuscript for The Murders in the Rue Morgue, the story that introduced what became the detective genre, filling a need that readers didn't know they had but couldn't get enough of once they realized it was there.

The other exhibition, where more of the mystery is revealed, is at the Free Library's Rosenbach Museum on the 2000 block of Delancey Place, where the literary fascination with crime and murder is documented from the 17th century on. The Rosenbach also ventures into recognizable fictional territory, showcasing the manuscript of Arthur Conan Doyle's Sherlock Holmes story  The Adventure of the Empty House.

That legendary bookseller and collector A.S.W. Rosenbach, who once lived in what is now the museum, was famously fascinated by detectives and mystery, a point that looms large in New Paradise Labs' Gumshoe.

The library contacted Whit MacLaughlin, artistic director of New Paradise, about staging some kind of performance -- a first for the Free Library -- and he spent many hours looking over the spaces in the old building, which is currently undergoing a major renovation.

MacLaughlin hit on an idea that would tie together the building on Logan Square with the Rosenbach and with Poe's Rue Morgue; the writer's former house at Seventh and Spring Garden Streets; Richard Gimbel, son of the department store tycoon; Starbucks; Jules Mastbaum; and Orion in the night sky.

And books.

"Whit wanted to see the nonpublic spaces," said Janine Pollock, head of special collections at the library. "He wanted to see what was behind this door and that; the more closed doors the better. And he started falling in love with the building and mystery and murder unfolding and a mysterious document."

All of which, said MacLaughlin, makes the library the star of the show.

"The clues actually lead to something," he said. "You find out exactly who did it and why. But, you know, you go into a library, I do, and sometimes I'm searching for this and I end up finding that. It's serendipitous. So much of our investigation now as consumers happens inside … algorithms. You go to Google and it sort of knows what you're thinking. As opposed to: 'I don't know what I'm thinking. How do I find something else?' How does the odd connection take place?"

The answer to that conundrum can be found in the library.

The search, led by Gumshoe "agents," takes visitors up to the Rare Book Department, where the Rue Morgue manuscript is on display (Poe's stuffed raven is perched nearby).

The trek winds through nonpublic rooms and down into reading-room stacks. Odd books are pulled out, words are found on different pages. The library's randomness takes over. Maybe this book just found is actually interesting. Perhaps it will change a life. Perhaps it is awful. Only perusal can help.

The performance descends into the mysterious bowels of the warrenlike building. Visitors are then propelled toward the Rosenbach and their smartphones to find the solution.

From the outside, the library reflects an orderly neoclassicism. Inside, away from the exterior's classical precision, the library becomes a cacophony of  voices colliding in a kind of intellectual Brownian motion that resists even hard-boiled detective work.

The several Gumshoe agents who guide their charges through the 90-minute show make the point that the novice detectives need to build their skills in "connections, dichotomies, serendipities." One says, "Look wide." Another tells charges to "write down what strikes you -- what makes sense, what doesn't make sense."

One Gumshoe agent says, "Fog keeps us from seeing clearly. But as far as the bureau is concerned, fog isn't necessarily a bad thing."

The library plays a dual role with readers. It induces fog by challenging received ideas, upsetting the reader's unchallenged beliefs. But those in the library see it quite differently. They see their charge as clearing away fog and chaos and bringing order and clarity.

"The essence of librarianship is to make order out of chaos," said Pollock. "We want to know: What is the person really looking for?"

Gumshoe runs twice a day, virtually every day until May 7 (the library is closed Good Friday and Easter Sunday). Gumshoe is free, but reservations are required. Information can be found and reservations made through the Free Library. Smartphones may also be used to "experience" Gumshoe.