Ariodante/The Turn Of The Screw, Richmond Theatre, Richmond

English Touring Opera is the latest in a line of stripped down, collaborative ventures running back to Britten's revelatory English Opera Group. And its current director, the Canadian James Conway, hasn't dodged the challenge of that heritage in selecting such ambitious projects as Handel's Ariodante and Britten's own supreme chamber opera, The Turn of the Screw, for ETO's autumn season. Whether the realisation matches the ambition is another matter.

Composed in 1735, Ariodante is one of Handel's later operas. But it is also one of his most dramatically cogent and musically rich - if correspondingly demanding upon its cast. The plot - out of Ariosto's Orlando furioso, but set by Handel, for some reason, in Edinburgh - is an archetypal tale of true love almost betrayed by jealous deception. In order, presumably, to bring home the drama's range of almost biblical dilemmas, Conway has set his production in a 19th-century manse on the Scottish coast - evoked by the designer Michael Vale with movable screens, stormy backdrop and Ibsenesque costumes.

The cast is, frankly, so-so. Louise Mott in the (originally castrato) title role spans her elaborate and hugely contrasting arias skilfully enough, if without real tonal allure. The counter-tenor Jonathan Peter Kenny as Polinesso brings a feral seductiveness to his wicked roulades, but tends to swallow the syllables of Conway's English version of the libretto. Joanna Burton as the traduced Ginevra took time to focus, but conveyed pathos as her plight worsened. And Laurence Cummings, directing his 15-piece orchestra from the harpsichord, offered an object lesson in style with his crisp ensemble, dance-like articulation and fine-spun phrasing.

Ten of the same players returned for Britten's uncanny recreation of Henry James's ambiguous tale, first staged in 1954. But the conductor Stuart Stratford's concern for detail in this eerily weightless score sometimes made for slack tempos - except, oddly, in the climactic scene, which he rushed, short-circuiting its inexorable build-up. Maybe he was affected, in turn, by a production less ambiguous than uncertain: teetering, under the direction of Adrian Osmond, between minimalism, realism and expressionism, and weakening Britten's alternation of vignette-like scenes with instrumental interludes, by continuous, obtrusive stage action.

A pity, this, for the cast is potentially good, with a touching Governess from Emma Gane, a youngish Mrs Grose from the capable Christine Botes, and a full-bodied Miss Jessel from Catherine Griffiths. But it is never clear whether the children, convincingly sung by Rebekah Coffey and William Sheldon, are complicit in their corruption by the ghosts or menaced. And it makes little sense to have the lyric tenor Christopher Steele insinuating Quint's suggestive cantilenas while presenting him as a sadistic oaf hurling Miles around.

For all this, the applause at the end showed that Britten's genius for timing and intensity had triumphed again.

Touring to 29 November (020-7833 2555)