With a title plucked from the back catalogue of Jacobean crooner John Dowland, and a plot somewhere between Marlowe’s Edward II and Game of Thrones, this tasty, twisty little play has a lot going for it. Steeped in literary references and historical assignations well away from your average History or English syllabus, it’s a story few will have encountered, but its political machinations feel only too familiar.

Put simply, back in the early 17th century, King James I took as his favourite a young social climber called Robert Carr. Carr was actually working with his friend Sir Thomas Overbury who wanted to wield influence over the crown. But Carr got greedy, and abandoned Overbury after falling head-over-heels in love with the bewitching Lady Frances Howard. Together they plotted Overbury’s murder, and ended up in the Tower of London - an everyday tale of cutthroat landed gentry.

In 2018, the Globe Theatre mounted a performance of Sir Walter Raleigh’s treason trial, using as script the original court transcripts from 1603, and allowing the audience to act as jury at each performance. It was exciting. We got to decide whether Walter would live to sail another day, or have his bowels removed while he was still alive and his head chopped off. (Thankfully, on the night I was there his bowels remained undisturbed.) Virtue’s Cloak captures some of that authentic Jacobean style, using a combination of surviving speeches and letters, alongside plenty of original composition from writer/director Andrew Raynes.

But Virtue’s Cloak isn’t just a courtroom drama. It imaginatively depicts the key scenes in this sordid tale, with plotting between Overbury and Carr, romance between Carr and Howard, petulant kingship from James, and plenty of incriminating letters being thrust in guilty faces. It has the ingredients to be a juicy romp in the style of The Favourite or even the bitchy backstabbing of Les Liaisons Dangereuses. And while it’s certainly fun, there’s a certain stiffness in the staging that works against the aura of delicious intrigue it’s aiming at.

The awkwardness stems from the stylistic difference between the authentic text that opens and closes the play, and the newly-written script in between. Raynes sometimes opts for making his characters speak in modern vernacular (Carr, on breaking his leg in front of the king, lies on the floor saying, ‘Fuck, fuck, fuck!’), but sometimes has them ape a semi-Jacobean style (‘Please – your husband. He is a murderer’ – ‘Leave me alone!’). Counter-intuitively, it’s the contemporary style that really works well, whereas the cod olde Englishe sounds just a bit too fake. The characters tend to declaim at each other in a style that seems intended to be precise and cold, but sometimes comes out as flat and perfunctory. There’s a fine line between formal and stilted, and Virtue’s Cloak treads it carefully like a tightrope walker. It doesn’t fall off, but it does occasionally dip a toe either side. It might work even better if the switch between ‘real’ old dialogue and modern script were more demonstrative.

That said, the atmosphere of a political spider’s web building up around the unfortunate Overbury is skilfully constructed, and the deliberately cold, distancing style, when it works, works really well.

There are other elements to enjoy here too. In place of an expensively decorated set, the production makes extensive use of 17th century music (which makes sense since the title itself is a song lyric). The almost continuous soundtrack does effectively create the illusion of a time and place, almost like watching Peter Greenaway’s 1982 period classic The Draughtsman’s Contract. The programme too deserves praise: it’s one of the best I’ve ever seen at a student production: printed on parchment-coloured paper and decorated with convincing woodcut embellishments (the colour photos nicely matching the deliberate clash of styles in the script). They even give you a free copy of Overbury’s sanctimonious poem 'A Wife', which Frances Howard the Countess of Essex was so offended by that she agreed to participate in his murder. In those days the poison was mightier than the pen.

So Virtue’s Cloak is very much a curate’s egg. It’s boldly original, and proudly dusts off a forgotten shelf in a rarely-visited corner in the library of British history. It also admirably gives roles to a cast of first-time actors, who deliver the show with impressive style in a sustained tone. But in its efforts to be semi-Jacobean and coolly detached it does sometimes feel flat and undramatic. Robert Carr doesn’t quite match up to Piers Gaveston, and Frances Howard isn’t a patch on Cersei Lannister. They just need a bit more nastiness. Perhaps that cloak should conceal a few daggers.