People in search of a “show” might not want to see Ariane Mnouchkine’s seven-hour “Le Dernier Caravanserail (Odyssees),” much as people looking for a painting to match their couch shouldn’t buy a Picasso. Gorgeous it may be, appealing and initially accessible, but the great ones aren’t easy to live with. Shrugging off the usual limitations of the theater, “Le Dernier Caravanserail” (translated literally as “The Last Caravan-Stop”), reduces all the silly distinctions among art, politics, and philosophy to semantics.

There’s no wonder we rarely come across work that poses a real challenge – audiences now get impatient after the 90-minute mark. And while careful, clever observations can be made in miniature, when it comes to vast, messy, world-size issues, only an epic will do. The epic that all epics hearken back to, Homer’s “Odyssey,” follows one man whose roots have been torn up by war – and now Odysseus has 17 million fellows. At least, U.N. High Commissioner for Refugees starts the counting there, but others figure that perhaps one in every 200 people is displaced.

Somehow, Ms. Mnouchkine and her Theatre du Soleil in Paris muster the hubris to tackle the plight of refugees – and not just a single story of eviction, either, but the problem in general. Where every other theatrical treatment devolves into either tendentiousness or hopeless sentimentalizing, the Mnouchkine team applies an encyclopedic care to “Odyssees.” They pile story upon story, often told in nearly wordless scenes, separated by letters, testimonials, and poems written by the exiled.

Some episodes beggar description. A river crossing, with the entire stage covered in billowing gray silk, rocks with the same exhilarating violence found in nature. Another scene at sea, again with players nearly vanishing under roaring waters, re-creates Australian coastal police turning back drowning boat people.

Throughout the piece, no actor ever touches the ground – they step between rolling platforms, pushed at top speed by players not in the scene. The effect, soundless and cinematic, has its own meaning. Not only have these migrating peoples lost contact with solid earth, but it takes the maneuverings of many to keep them on their way.

The piece follows one pattern, incessantly alternating between transcribed testimony projected on a back wall (again, gray silk) and enacted scenes of escape, oppression, or hope. Recordings of refugees make up the bulk of the interstitial texts, anything from a man’s recollection of the day he lost his daughter while smuggling her across a river to a revolutionary cry from Tehran (“Poor am I if I don’t get drunk on the sun!”).

The scenes, however, are largely improvised by Ms. Mnouckine’s 75-person company, which leaven the despair with humor and/or romance.

A French refugee camp called Sangatte, which once housed thousands trying to make it over the channel into England, recurs as a setting. We see old women throwing themselves at a moving train, hoping to hitch a ride through the Eurotunnel, nurses breaking their hearts over their patients, or the traffic in female flesh that goes hand-in-dirty-glove with these sites of human desperation. Sangatte, we learn, at Engtition refugee’s reality: Already there are no options, and those are diminishing.

Seven hours, with an hour break for dinner, feels (perhaps intentionally) like a working day, and though Ms. Mnouchkine shies away from calling her shows “research,” they most certainly are community labor. She loses some of her die-hards in the final stretches, possibly because she begins to fall into maudlin patches that the first section avoids. A sure sign that our heartstrings are in for a tugging: the multiplying presence of wide-eyed child actors and an increase in the number of rolling trees. Even the astounding work of musical composer, performer, mixer, and birdcall whistler Jean-Jacques Lemetre begins to get a little string-heavy in the second half.

But what they have – and the American theater does not – is grandeur. Sadly, in our theatrical climate, where we grow compact pieces in a five-week hothouse, scope is the first thing sacrificed. Artists from America who like a larger scale must either work completely outside the system (the Wooster Group) or in other countries (Robert Wilson). And yet, this piece, with 60 scenes and a message of grave importance, is by no means inaccessible. It is a vortex of emotion, meaning, and activism – and a welcome place of refuge.

Until July 31 (Lincoln Center, 212-721-6500).