Don’t be late to Preston Old Church: you’ll find the doors sealed against you, the actors and the audience closeted within. There, among the fading frescos of a beautiful but damaged building, a cast of just five people tells the tale of Macbeth. It’s a fitting metaphor for the fate of Shakespare’s most notorious tyrant - trapped in a decaying, shrinking world, surrounded by enemies and demons of his own making.

This is, of course, the Scottish Play, and touring company This Is My Theatre give it a distinctively Celtic tone. Their bold adaptation is filled with song: some of it is reverential, matching the clerical venue, but most of it is akin to a sea-shanty or a Gaelic folk tune. Each song is impeccably delivered, and each sets the perfect tone for the unfolding plot, sometimes haunting, sometimes threatening, occasionally chilling. The cast mingle with the audience - chanting from the back and sword-fighing in the aisle - adding a visceral intimacy to the darkness of the bloodstained tale.

Most Fringe Macbeths trim a few scenes, and this one’s no exception; but where many versions rush the earlier scenes to make time for the “deepest consequence”, Sarah Slator’s adaptation instead throws sharp focus on the actual murder. It changes the complexion of the piece, and reveals facets to Shakespeare’s story which - though I must have seen Macbeth twenty times - I’ve never truly appreciated before. We see the runaway momentum of the plan, and the desperate urgency of the cover-up; we feel the sheer grisliness of what happens just off-stage.

Ethan Taylor plays Macbeth as a well-groomed, self-confident war hero, a man who wouldn’t be out of place on our TV screens today. But every now and then, when nobody’s looking, we get a glimpse behind the façade; there’s a quiet moment, a knowing look, an acknowledgement of the ambition lurking within. Eleanor Toms makes Lady Macbeth every bit her husband's equal: when the two quarrel it’s natural, convincing, and pacy. Toms has a stunning additional talent too, which they hold in secret reserve till the moment of greatest effect - you'll get to enjoy just before the bedchamber scene.

The three male witches serve as an ever-present chorus - literally so, since it’s they who deliver the majority of the music and song. Filling in for all the minor roles, they act as Macbeth’s informers and gatekeepers, controlling the boundaries of his increasingly isolated world. They bring the dagger which Macbeth sees before him; they entrap him, not just with promises, but with wine and friendship too. Banquo’s appearance at the feast is a masterpiece - an unconventional interpretation which is both elegant and creepy, and cleverly evokes Macbeth’s growing paranoia.

You do, I think, need to be familiar with the story - if you don’t already know what happens to Macduff’s wife, for example, you may struggle to understand the abbreviated telling of that part of the plot. The fact that Toms plays Banquo as well as Lady Macbeth is also quite confusing. But for those in the know, there are a lot of clever tweaks to spot and enjoy, including a daring reshuffle at the very end which I felt - dare I say this? - was an improvement on the original.

This isn’t a conventional Macbeth, but it’s something even better: a well-conceived and stylish adaptation, confident in its voice and at home in its venue. No matter how many times I see this script performed, it always offers something new. And of all the Macbeths I’ve encountered in my years at the Fringe, this might just be the most evocative... and most thrilling.