THE Classic Thriller Company has grown out of impresario Bill Kenwright's successful ventures with The Agatha Christie Theatre Company.

Christie's thrillers are bullet-proof; pretty much guaranteed box-office gold dust, whether taking The Mousetrap on a road trip around the country or producer Rebecca Stafford transporting The Witness For The Prosecution from a York council chamber to County Hall, London.

Predicting hits beyond Christie is more difficult: Stephen Mallatratt's adaptation of Susan Hill's The Woman In Black has grown from low-key Scarborough beginnings at the Stephen Joseph Theatre in 1987 to full bloom in London and on regular tours, while revivals of Patrick Hamilton's Gaslight go well.

Director Roy Marsden and the Kenwright-backed Classic Thriller company look to freshen the thriller tastebuds with big casts taking new adaptations on long regional tours. Last year it was Ruth Rendell's rather strange whydunit, A Judgement In Stone, a puzzling piece that had you wondering whytheydunitall.

Now, Marsden is directing Antony Lampard's new script for Edgar Wallace's The Case Of The Frightened Lady, a return to the more popular whodunit format, with a pair of regulation detectives, Gray O'Brien's thorough, if arid Chief Superintendent Tanner and former Harry Potter film regular Oliver Phelps, in his professional stage debut as dour Detective Sergeant Totti, doing the spadework.

They have arrived at Marks Priory, the seat of the Lebanon family, whose lineage goes back to Agincourt, after one of the many serving staff, Studd (Joshua Wichard), has died, strangled by a red cord. Apparently there used to be a staff of 70, but now there are only 15, most of them seemingly in this play, as recently widowed Lady Lebanon (Deborah Grant, splendidly grand in the show's best turn) and oddball son Lord Lebanon (Ben Nealon, in need of a posher accent) must deal with reduced circumstances in 1932.

Footman Gilder and Brook (Simon Desborough and Callum Coates) do little but listen in from the shadows; Mrs Tilling (Rosie Thomson) was having a fling with Studd; physician Dr Amersham (Dennis Lill) appears to be running the house; and Lady Lebanon's young assistant, Isla Crane (April Pearson), has more of a case than anyone to be the frightened lady of the title.

Everything we see happens in the hall, a large if somewhat blandly imposing canvas that does not play its part in the way that scenery does in Blithe Spirit or The Woman In Black, save for characters emerging from the shadows. We hear screams, noises off, red cords come and go; mysterious blank cheques are signed by Lady Lebanon; a desk is the busiest prop.

The pace is steady, the drama is steady, the performances are sturdy, but Wallace's story and Marsden's production feel old-fashioned, neither frightening nor much fun to watch.

The Case Of The Frightened Lady, The Classic Thriller Theatre Company, Grand Opera House, York, until Saturday. Box office: 0844 871 3024 or at atgtickets.com/york