A samurai is found dead in the woods near Kyoto.

There are four eyewitnesses with four different versions of the incident and, somewhere between them, the truth.

This is the promise of the whodunit classic “Rashomon,” adapted for the stage by Kay and Michael Fanin from the iconic 1950 Akira Kurosawa film (in turn based on the stories of Ryunosuke Akutagawa).

Thunder River Theatre’s production, which opened last weekend and runs through July 2, doesn’t tip its hand as to what is fact and what is falsehood. It makes for a riveting theatrical experience.

Our narrators are the impressionable woodcutter who found the body (Nick Garay), a wise priest who speaks in aphorisms (William Moseley) and a swindling, streetwise, cynical wigmaker (a scene-stealing Owen O’Farrell).

They dissect testimony from the bandit who admits to the samurai’s murder, the wife who survived the attack, the samurai who speaks from beyond the grave through a shaman, and the woodcutter himself.

Each version comes to life on stage as the witness gives their version.

Nathan Fox, one of four actors in the cast making a Thunder River debut, is thrilling in the lead as the bandit Tajomaru.

Fox is a commanding presence and gives a performance in many shades of gray — each version offering a slightly varied Tajomaru: Is he a menacing murderer and rapist lurking in the woods?

A bad boy lothario and lovable rogue?

A fumbling wannabe with less bite than bark and laughable sword-wielding skills?

We glimpse each of these incarnations, and Fox makes us believe each of them.

The other two principals in the flashbacks are the murdered husband — played by Travis McDiffet, also making his Thunder River debut — and Haley Thompson as his wife.

Both hold their own beside Fox’s Tajomaru with shape-shifting characters that evolve from each perspective.

China Kwan, in the single-scene role of the samurai’s wife’s mother, is lamentably the lone Asian actor in the production.

Coming in at a fierce one hour and 15 minutes, this production benefits immensely from an immersive scenic design of bamboo and vines, with dramatic lighting that puts the audience in the inky and mysterious forest outside the Rashomon Gate on the night in question.

That ominous mood is heightened by atmospheric live drums, chimes, gongs, bells and pipes.