Pilobolus, the madly popular, ever-evolving dance troupe, returned to the American Dance Festival with a program many shades darker emotionally than viewers may expect, but filled with intriguing lighting effects. The lighting and its shadows, or the shadows and their sources, are as important to these works as the dancers themselves.

The ADF-commissioned world premiere that ends the program is in fact called Darkness and Light. It is choreographed by puppeteer Basil Twist, along with Pilobolus artistic directors Robby Barnett and Jonathan Wolken, and the performers, and its action all takes place behind a scrim. You do not see the dancers; you see a pageant of dancing shadow-shapes that only occasionally look human or even earthbound, cast in a rich palette of darks and moving in an ethereal world of light. At the beginning, the curtain comes up on the dancers and their light projection gear standing ready, and then the scrim comes down before them. At the end, the dancers, drenched in sweat, are revealed again, to encourage your belief in the improbable fact that all this bewitching imagery had been generated right then, in real time, by people rather than digital code.

It is a remarkable and sometimes beautiful piece of image-making, but its disembodied nature filled me with sadness. Following as it did Martha Clarke’s 1979 meditation on aging, Nocturne, I felt I was witnessing some kind of afterlife for dancers. Nocturne’s solo was beautifully danced by Renée Jaworski. Dressed in a froth of tulle and a bleak white head covering, in a crippled parody of grace she totters through a little dying swan dance before struggling off the stage. But behind the scrim, moving into the light, dancing was freed from ruined joints and wasted muscles in Darkness and Light. That of course was an illusion, the paradox driving the work: This free, floating, de-materialized imagery, these pictures made of light, could only be generated by the physical work of bodies — the existence of which we must take on faith, deprived as we are of sensory connection with them.

The shadow world has not yet overtaken the present world in the program’s other two works from 2008 — we still get to see the dancers. Razor: Mirror is strange and absurd with antic carrying on, somewhat in the manner of the Argentinian troupe Krapp, and its movements are jerky and hard-edged. Lanterna Magica is a smoother foray into the kinder side of darkness. It was lovely, but lacked the sense of inevitability that makes much of Pilobolus’ work so powerful.

Also included in the program is one piece that will be more recognizably Pilobolean to long-time viewers. The beautiful Symbiosis from 2001 is wonderfully performed here by Jenny Mendez and Manelich Minniefee. Its obdurate physicality and insistent interdependence give off a comforting glow in the heart of darkness.

The program continues June 20 and 21. See our calendar for details. At publication time, seats were still available for both days.