This rather quirky piece, based on Patricia Highsmith's 1955 novel with a debt to the film directed by Anthony Mingella in 1999, tells the story of Tom Ripley, employed by a worried American father to travel to Italy to persuade his son Dickie Greenleaf to come home to New York.

The two young men are meant to be friends but actually have never met. It is the first demonstration of Ripley's slippery "talent". What follows involves lies, murder, identity stealing and a certain amount of confused sexuality.

It's a magnificent central performance by Christopher Hughes as Ripley in a huge Hamlet-sized role. He is by turns awkward, manic, frightened, duplicitous and ruthless. Hughes has a knack of twisting round just a few degrees as he switches moods and personae and it's rivetingly entertaining. If I were star-grading Hughes separately from the rest of the show he'd definitely get five.

There is also some fine acting from Natasha Rickman as the troubled, attractive, puzzled Marge and from Adam Howden as Dickie – so very sure of himself in contrast to Hughes's screwed up Ripley. Congratulations to Suzie Foster on her simple but effective set too – a square raised white dias with a central hole which enables characters to emerge from beneath, behind and within it. There are some quite nice ensemble physical theatre moments in well established The Faction style. The rocking bus journey is fun, for example.

Beyond that, though, there are flaws. We are supposed, it seems, to see the piece as a quasi play within a play – or film in this case with camera men and crew occasionally calling shots and other instructions. As a device it is insufficiently sustained and doesn't work at all. Then there are the accents. Generally the voice work is acomplished but it's clear Ripley is an American so why does he use an English accent except when he's masquerading as Dickie? Francis Woolf's character unaccountably does the same. And oh dear, the length. A play of this type should not be almost three hours long.

The Talented Mr Ripley runs in rep at the New Diorama Theatre until 28 February