THIS thriller is, frankly, a masterpiece of chilling stage noir that will leave you questioning the very fabric of human reasoning and in The Case of the Frightened Lady, you will walk away from Windsor’s Theatre Royal having watched a masterclass in passive psycho tendencies, writes Paul Thomas.

This chiller is not for the faint hearted, and the ‘Royal’ was packed for Wednesday’s first night, so if you like your murder mysteries dark and edgy, then you’ve got what you want at this terrific theatre.

Building on the phenomenal decade-long success of The Agatha Christie Company, which sold over two million tickets around the UK, this is a belter from “the king of the detective thriller” Edgar Wallace of King Kong fame.

When Inspector Tanner is called in to investigate a ruthless murder at Mark’s Priory, the grand ancestral home of the Lebanon family, he quickly discovers that nothing is quite as it seems. As Tanner moves closer to the heart of the mystery he uncovers a shocking and closely guarded secret.

The story is a thriller that revolves around the Lebanon family. Lady Lebanon tells her son, Lord William Lebanon that he must marry his cousin Isla Crane to continue the family line. However, William has no intention of marrying Isla and matters are made more complicated due to Isla falling in love with architect, Richard Ferraby, who has come to Mark’s Priory to draw up renovation plans. At the same time, the strange behaviour of two footmen and the family physician add to the mystery surrounding the family and eventually rumour and speculation lead to a murderous conclusion.

TV favourite Rula Lenska (EastEnders, Rock Follies, Doctor Who) pictured below right, plays Lady Lebanon in the pivotal role around whom everything rotates and gravitates.

She is unnervingly gentle with an admiring malevolence which is palpable from curtain up.

There is a dark, but engaging evil about Lenska’s portrayal of a matriarch with a secret.

She shows a definitive motherly protective quality with razor-sharp claws hidden under an upper-class petticoat – a petticoat of protracted psychological manipulation.

Lenska is a revelation in this role heading what is an all-star cast, all of whom turn in superb performances.

Gray O’Brien, one of TV’s most popular actors, known for his memorable roles in The Loch, Peak Practice, Casualty and as Tony Gordon in Coronation Street is creatively genius as Tanner. His ability to unearth the underlying secrets of the Lebanons is played superbly with an deft ability to portray a copper’s graft backing up his top-billing.

Denis Lill from long-running drama The Royal and Only Fools and Horses is wonderful as Dr Amersham.

Charlie Clements, who played the much-loved character of Bradley Branning in EastEnders is a brilliant side-kick sergeant Totti to Tanner.

April Pearson (Skins) is a cool-as-a-cucumber Isla with some direct yet understated acting and Agatha Christie Company stalwart Ben Nealon (Soldier Soldier) is a cracking Lord Lebanon.

This is a classic thriller with classic acting and is not to be missed.

So ditch the tellybox or set to record and get yourself down to the ‘Royal’ for one hell of a murder mystery that refuses to let you sleep well when you get home.

The Case of the Frightened Lady. Theatre Royal Windsor, until Saturday, January 20.

Box office: 01753 853888 or theatreroyalwindsor.co.uk