Like many non-professionals watching the installation this month of the set for When the Rain Stops Falling, I've been at a loss to describe its unusual, striking appearance as it's taken shape. So one day last week, I asked David Korins, the set designer, to clue me in as to what had been going on, shortly before he headed over to the Mitzi Newhouse theater to check on the load-in crew's progress.

First, Korins gave me the precise, pitch-meeting description of the set: "It's an attempt to create a full environmental experience for the audience. We're making a ceiling that becomes an emotional barometer for the entire play. It can, at times, be a roiling, scary sky, the bottom of the ocean, or ominous bags of water. It creates a tapestry of both emotional and literal weight."

Thinking of the spectacular plastic canopy over the stage, I asked Korins for a more nuts-and-bolts version of the set's sales pitch. He replied: "I said to the powers-that-be: 'I want to wrap the ceiling in plastic and pour water on it.' I've done water onstage before, and pools of water, but I have never done water overhead."

How was all this reflected in the set design process? "When we made a model of the set, we had to make it twice the usual size to represent accurately what the design would look like in the space. But we could only go so far with a model. We didn't do a full-out drafting, because the scene shop said that it would takes weeks to represent the set in drawing form."

The key question in the load-in, Korins continued, was: "How are we really going to attach this stuff to the ceiling?

By "stuff" Korins means that plastic canopy. The attachment of it to the top of the Newhouse was a trial-and-error process between Korins and the crew. "It was a full collaboration," he said, "and a wonderful experience. It's also a challenge for the lighting designer [Tyler Micoleau] to work with and around what we've been doing."

Korins originally thought the set's puddles would be quite large. Eventually, however, he and the crew realized that they'd have to cut back on the volume of water.. "Think about what happens when you spill just a little glass of something," Korins explained. "It seems to make such a big spill, even if it's only a few ounces of liquid."

Perhaps Korins' biggest technical challenge came before the load-in started. He said: "I wanted to use Visqueen" - a professional type of polyethylene film that usually comes in roll form - "for the plastic but I knew that Visqueen would be an issue in New York. It's not fire-retardant, and in New York you are required to use fire-retardant materials." Korins thought his only choice might be to use fabric and paint it to look like plastic, an option that displeased him.

Then fate, in the form of a meeting Korins happened to be having with Rose Brand, a theatrical supply company, intervened. "They were showing me new products," he said, "and one of them was a clear vinyl. I was over-the-moon about it, because it's fire-retardant so I knew it would be the solution." Korins said that the material, which can be printed on, was specially made for LCT's When the Rain Falls. "This is the first time it's being used in a theatrical production. That's pretty exciting."

BRENDAN LEMON is the American theater critic for the Financial Times and the editor of lemonwade.com.