And much, much more.

PARIS — You can’t always expect to understand the work of Romeo Castellucci. But you’re sure to be awed by its beauty.

Especially when the Italian director — really, a polymathic theatrical artist — stages opera. His productions are rich in symbols and enigmas; each movement leads to a picture-perfect tableau….Mr. Castellucci’s latest project, Scarlatti’s “Il Primo Omicidio” (“The First Homicide”), which continues at the Paris Opera’s Palais Garnier through Feb. 23, is…relatively direct, yet still striking.

“It’s a portrait of Cain,” Mr. Castellucci said of Scarlatti’s 1707 oratorio, an account of the Cain and Abel story, in an interview under the ornate chandeliers of the Garnier’s grand foyer. “But it’s really about innocence.”

The switch from adult singers to children happens the moment Cain murders Abel. “We are in the domain of childhood,” Mr. Castellucci said. “It is a childish mythology.”

A story of jealousy and murder, in his telling, becomes one of rediscovering lost innocence, of adults in search of their youthful doppelgängers….a journey abounding in imaginative stage magic — with layers of lighting and scrims, Mr. Castellucci conjures vast Rothko canvases that have the soft seamlessness of a James Turrell — reaches its end.

The soprano Birgitte Christensen, center, as Eve.CreditJulien Mignot for The New York Times

For the scene in which Eve learns she will be a mother, Mr. Castellucci thought of the Annunciation — the angel Gabriel delivering the news to the Virgin Mary that she would give birth to Jesus. So he turned to “Annunciation With St. Margaret and St. Ansanus,” an Italian Gothic triptych by Simone Martini and Lippo Memmi that now hangs in the Uffizi in Florence.

But he turned it upside down. As Eve sings of her coming motherhood, the massive altarpiece is lowered, slowly, above her head. “It’s a kind of guillotine,” Mr. Castellucci said. “A menace.”