Choreographer Noémie Lafrance is clearly a good talker. In order to present her most recent piece, Agora II, she had to cajole Brooklyn park officials into letting her go into the detritus-filled, abandoned McCarren Park Pool, bring it back from the brink of demolition, and then stage a dance piece in it with a cast a hundred-strong.

Admittedly, this is a coup she won last year, when she staged the first Agora in the empty basin, but still, the woman has fast-talked her way around a load of bureaucracy. Now, she starts in on us.

Unfortunately, it’s the patter of “Agora II” that is impressive, not the actual piece. Just like those conceptual canvasses that use their wall text as a crutch, this is work that depends on its supporting materials, not its power, as an experience. Without the tickets, which double as instruction manuals, and the support staff, which gives out marching orders, the evening consists of tired rushing about by “eccentric” characters who wouldn’t pass muster at Coney Island’s Mermaid Parade. For a show with rolling mattresses, office chairs, and a fleet of twinkling scooters, it’s amazing how totally it fails to move us.

Billed as a “choreographic game for one thousand bodies,” “Agora II” requires a bit more of its audience than the usual sit, shuffle, and stare. Those holding “participant” tickets must memorize simple gestures and stand ready to obey any flag-waving company member. If, for instance, you are in the “Flock” team, the whole gaggle of dancers will whizz by you, waving a “Flock” sign so that you might stand up and dash around with them. For observers, mind you, this audience participation looks suspiciously like boring running back and forth, of which the dancers themselves do plenty.

The program swears that the evening has chapters. Well, no, but it does have describable elements. First a fellow painted blue stands on top of the mammoth gate structure, waving, or possibly pointing out the North Star.Then, a mummified body is fed into a grate in the center of the pool. Then there is a vast stretch of clichéd mini-dramas. (You know from the get-go that someone will eventually emerge in a wedding dress.) A woman fights with Jesus over her cup of tea; a fellow trying to watch television scooches slowly across the cement; a couple of Phyllis Dillers — called Delphies — in pink fuzzy slippers try to keep out of the bicyclists’ way. Somehow, it manages to be overly precious and calculatedly amateurish at once. Worst of all, the company occasionally breaks into limp dance routines: A capoeira-style hip-throw here, a little electric slide there.

Ms. Lafrance’s devotion to unusual spaces has paid off in the past — her exploration of a stairwell in 2001’s Descent made her name in New York, and she sees possibilities where other people see parking garages. To be fair: Her resuscitation of the McCarren Park Pool is in itself cause for joy. Though it may never function as a water park again, the old cracking brick fortress certainly has dignity and scope and vastness on its side, and it cries out for work that can fill it up.

Then why is this work such a bellyflop? Certainly, Ms. Lafrance cannot be accused of having too small a vision, but she can be tackled for overreaching.This is the choreographic version of having eyes too big for one’s stomach. She hasn’t the faintest idea of how to use the pool’s volume, or how to expand and contract the audience’s experience of it, so it constantly works against her. She has masses of people, yet still fails to strike a single note of spectacle — even riots have a better sense of execution.

Ms. Lafrance hasn’t grasped that key element of site-specific work: the frame. She may have wished to do away with it, to merge us all into a big performer–observer mush, to live up to the inclusivity of her title’s reference to the marketplace. But her intentions and her critical lingo can’t help her — in the McCarren Park Pool, it’s either sink or swim. And this is one piece that goes straight to the bottom.

Until September 30 (Lorimer Street, between Driggs and Bayard avenues, 718-388-6309).