Jephtha, Coliseum, London

Katie Mitchell's searing production of Handel's last oratorio, Jephtha, has the look of a classy wartime serialisation - Fortunes of War, or the like. But its visually handsome, slow-burning first part in no way prepares us for what is to come. Only as we emerge shaken, not stirred, from the final denouement is the scale of Mitchell's achievement really driven home.

She has taken an old and intrinsically static form - oratorio - and brought it off the page to animate the stage in ways that even this most inherently dramatic of composers would have found disarming. It's called making a drama out of the merely dramatic.

The premise is as old as time. Ambitious military leader, Jephtha, makes a private pact with God: victory in exchange for sacrifice. The first living thing he sees on his return shall die. With Mozart's Idomeneo, it was his son; with Jephtha, it is his only daughter. And on the eve of her marriage. So, a potent situation, but one that Handel duly "formalises" for the concert platform. The chorus lead off a series of tableaux: concentrated, episodic and emblematic as befits the form.

But Mitchell stunningly creates a credible ebb and flow to the narrative, "dissolving" cinematically from one episode - one "number" - to the next through the use of black masking. Shifts in time, place and emphasis are achieved in seconds. Essentially, Mitchell and Vicki Mortimer, her designer, have contrived their own instant editing facility. You could almost be watching a film.

The setting is a war-torn hotel - military base, hospital, makeshift headquarters - somewhere in Eastern Europe. The urgency of human traffic and noises off stage suggest the close proximity of battle. We are in the eye of the storm. And it is a tribute to Mitchell's skills and those of the English National Opera chorus that even the formalised set-pieces are so seamlessly integrated into the narrative. So naturally does the chorus function as a group of individuals, that you can be halfway through a double fugue before registering their collective purpose.

But Mitchell's staging rises to harrowing levels of emotional truth when Jephtha's pact comes back to haunt him. Holding court in his moment of triumph, we see only his back, as Iphis, his daughter, in virginal white, descends the hotel staircase. And we can only imagine the expression on his face as his hand clutches at the chair in abject horror at the consequence of what he has just seen. The physical "scream" that Mitchell then creates as he violently overturns chair and table is but the first of a series of shocking and unflinching cris de coeur with which she punctuates the climactic numbers in Handel's moving score.

It is nobly served here under Nicholas Kraemer's judicious direction. One of the anticipated and most terrible highlights comes as Mark Padmore's Jephtha promises his only child a host of angels to carry her to eternity. But as one achingly beautiful stanza succeeds the other (and the purity of Padmore's delivery here is a thing of wonder), we almost don't notice that he is tying a blindfold around her head. Sarah Tynan (Iphis), her legs buckling beneath her, then takes her music to daring extremes: whitening and intensifying the sound by draining its natural beauty of vibrato. She breaks your heart. As does Susan Bickley, whose mother's rage is largely conveyed in silence, and Robin Blaze (Hamor, Iphis's would-be husband) whose name proves appropriate to the exultancy of his coloratura.

In the end, the Angel of the Lord may bring clemency for Iphis, but there is no real salvation in the gesture. Jephtha is left to sign off his war documents and, with them, his family. That's Mitchell's truth. Unmissable.

To 15 June (020-7632 8300)