In the film Shakespeare in Love, dramatist John Webster is portrayed as a death-obsessed boy with a pet rat, but - as his 1623 tragedy The Duchess of Malfi shows - he grew up to be a moralist and a poet of darkness. As director Gregory Floy (who co-directs with Sue Lefton), says: “I’m a great respecter of verse - Webster used it for a purpose. The spring and rhythm of the verse conveys the emotional state of the characters.”

A “lusty widow”, the young Duchess of Malfi, decides to marry her steward, Antonio, in secret and in defiance of her two brothers, the Duke Ferdinand and the Cardinal. But, betrayed by the malcontent Bosola, who has been placed in her house as a spy, the Duchess and Antonio suffer the vengeance of the brothers.

“The glory of Jacobean drama,” says Floy, “is the directness of language - there is no subtext: what you say is what you mean.”

And despite the text’s occasional obscurities, “there’s a lot of dark comedy and use of tricks.” For example, “the Duchess is tricked into believing Antonio is dead when she’s shown waxworks of his corpse, and the Cardinal’s mistress is tricked into kissing a bible which is covered in poison”.

In Webster’s imagination, Renaissance Italy is a fantastical place thick with plots and intrigue. So although Floy says that the production’s design is a bare stage, with minimal props, the space will be hung with curains, “which can be used to convey the idea that everybody’s spying all the time”.

To underline that this story of a dysfunctional ruling family has contemporary echoes, the costumes will aim to convey “a mixed feeling of Renaissance and modernity”.

Is the Duchess an enigmatic character? “You could take a very feminist line on her character,” says Floy, “but that is reductive, and cuts out the complexity. What we do know is that she rules a duchy and is her own woman. She marries her steward because she’s a wilful woman, but also a whole woman, passionate as well as perverse.”

The Duchess plays a dangerous game, flirting openly with Antonio, but “the excitement of illicit love finally gives her away,” says Floy. In the end, she believes “enough in God not to commit suicide when her family is destroyed, and faces death grandly.”

The brothers forbid her remarriage for different reasons. “The Cardinal is a controller,” says Floy. “He’s not opposed to another marriage as long as he can decide on the husband. Ferdinand just doesn’t want her to remarry,” and perhaps his fury conveys an element of incest.

The key to the character of Bosola the malcontent, says Floy, “is that he’s spent years in the galleys. To survive that, he had to create another world for himself. Anybody who’s survived that can survive anything.” Bosola knows who he is and his place in the cosmos.

Aleks Sierz Until April 15. Tickets: 01206 573948