"I only want to talk to you.” The latest ensemble work by theatre's most dazzling innovator, Robert Lepage, takes utterance as its premise: the human voice, its capability and limitations, the layers of meaning in the simplest exchanges, the secrets leaking out in the shattering silence between words. Presented in a three-part, nine-hour trilogy performed in four languages, Lipsynch traverses decades and continents as nine stories of nine interweaving lives unravel before our astonished eyes. Often the journey is excruciatingly intense, exquisitely beautiful.

Sometimes it loses its way, dallying too long with a character to whom we have barely been introduced or indulging in some slapstick farce that, after the sublimity of its more refined moments, feels irritatingly inconsequential. But to experience it at its long-awaited world premiere is to have been present at the birth of a work of art, an arrival that is at times messy but that evokes a sense of wonderment.

In the cabin of a transatlantic jet sits a young woman, pale and motionless as a doll, her baby on her knee. An opera singer returning from a tour notices something is wrong. As the music that shapes and expresses the singer's world swells, she communicates her anxiety to the crew. The woman's lifeless body is moved; the course of the crying infant's existence, and that of the singer, is irrevocably altered.

Gradually, other voices join in what becomes a complex and multilayered soaring song of humanity. The baby, adopted by the singer, grows up and makes a feature film in which he re-imagines his family history. A prostitute unpicks her painful past, long buried in denial and deception. A neurologist is torn between the rationality of science and life's impenetrable mysteries. A lonely Scottish detective struggling to solve a murder case is distracted by the departure of his French wife, who says he is “difficult to communicate with”. From Nicaragua to Hamburg, from Vienna to London, on movie sets, in cafés and Tube carriages, churches and seedy city streets, opera houses and operating theatres, lives are torn, scattered and finally healed in a devastating final image of tender cradling that recalls a classical pietà.

Individual details are set against a backdrop of larger events - revolution in South America, war in Europe, the double-speak of modern politics oozing from radio news broadcasts. Lepage fuses the particular with the epic with customary élan. A blend of film and theatre techniques delivers any number of startling trompe l'oeil effects. Sounds and images are bewilderingly and brilliantly juxtaposed, often with huge emotional impact.

The dialogue sometimes falters, and some sections of the work cry out for distillation. But it is as familiar as everyday routine, fantastical and unpredictable as dreams: once seen, and heard, never forgotten.

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