Though I’ve just begun writing this review, I am already at a loss for superlatives. NATASHA, PIERRE & THE GREAT COMET OF 1812  has to be one of the most fantastically alive and rapturous theatrical productions I’ve ever seen. THE 19th century Russian novel has come to dazzling life at the American Repertory Theater in Cambridge after premiering off broadway and heading back to NYC and Broadway next fall.

Ripped from the pages of Tolstoy’s epic “War and Peace,” this “novel” production zeroes in on 70 pages of the love affair turned romantic scandal between beautiful ingenue Natasha and dashing cavalier Anatole who tries to take her for a ride while her fiance Andrey is off fighting in the Napoleonic wars, leaving her prey to this Russian wolf. The whole glamorous,  heartbreaking escapade has been turned into an electropop opera with a gorgeous, dynamic cast cutting a swathe through the audience and every inch of the theater.

You will FLIP as soon as you walk through the door. The entire theater, top to bottom, back to front has been wrapped in red velvet, hung with glittering mirrors, chandeliers, paintings;  the audience is ensconced in banquettes among layers of tables by lamplight, waiters swirling about hoisting vodka and serving pierogies (delicious!) There’s a live orchestra dead center with violinists strewn about the room stringing out their tunes in a phantasmagoria of 19th century Russian opulence.  This all-enveloping set (designed by Mimi Lien a 2015 Mac Arthur’Genius Grant Winner) is a salon, a grand opera house, a ballroom, and the seat of the most heated passions, where an exposed arm, an uncloaked shoulder, the curve of a tender neck might ignite erotic fire, invite seduction, and lead to ruin. I was breathless before anything even happened.

And then it did. Book, Music and Lyrics by Dave Malloy distill Tolstoy’s language, so the details of plot are crystal clear with a potent through line to the characters’ inner lives. We are told straight out that all “these Russian characters have 9 names” so  “you’re gonna have to study up a little bit,” and that “Natasha is young,” “Anatole is hot,” “Helene is a slut,” and “Andrey isn’t here.”  Later the ensemble reminds us that “In the 19th century we write letters,” then suddenly an audience member is dispatched to deliver a love note to our quivering heroine!

The effect is delightful and ingenious, playfully calling attention to Tolstoy’s narrative style while drawing us into the emotional heart of the tale. Modern melodies wrap themselves around classic structure, acoustics and electronics intertwine. When Natasha (the lovely, deeply affecting Denee Benton) first meets Andrey’s spinster sister Mary (Gelsey Bell), their discordant interaction is expressed in piercing, unresolved musical dissonance. Immediately Natasha’s lushly beautiful soprano intones the aching aria “No One Else” which seems to erupt from her very soul.

All of the voices are uniquely well-suited their parts: Lucas Steele’s roguish Anatole sings with an urgent tenor on high alert. As Natasha’s stern godmother Marya D, Grace Mclean’s growling alto is terrifying. Scott Stangland as the disaffected Pierre performs with a ruefulness that primes him for an epiphany to come. (Josh Groban will reportedly make his Broadway debut in the part next September.)

Rachel Chavkin directs it all– singers, dancers, actors, musicians, moonlight and stars– like a kaleidoscope endlessly unfolding. It’s hard to know where to look during the climax of ACT I, the grand ball, when a riot of revelry spills out 360 degrees and we are caught up and swept along in a dizzying tableaux of decadence and merrymaking.

But the best is yet to come. The climax of ACT II culminates in a stunning piece of stagecraft that cuts to the quick of Tolstoy’s themes of love and truth. The dispirited Pierre is suddenly stopped alive in his tracks by a celestial event; all at once the walls of the theater seem to fall away and we find ourselves tiny specks “beneath a firmament of stars” along with Pierre who speaks, now illuminated “with uplifted soul,” and full of compassion for Natasha, himself, and what fools we mortals be. It’s a deeply moving theatrical moment and one I won’t ever forget.

You must see NATASHA, PIERRE & THE GREAT COMET OF 1812 at the A.R.T. in Cambridge only through January 3!