Death and Poetry was inspired by two books (although one certainly didn't start life as a book): Macbeth by William Shakespeare, and Traces by Patricia Wiltshire.

I first read Traces in the summer of 2022, and it fascinated me. It documents the author's career as a forensic botanist, a highly specialised role in which forensic technicians use traces of plant matter to identify where an object or person has been to help shed light on crimes.

For example, in a chapter called ‘Searching and Finding’, she describes how she uses plant evidence to go on a mental journey, imagining the route that a perpetrator or a victim must have taken to arrive at a crime scene.

‘An image of a place suddenly forms in my head. It is not as magical as it might seem. It is an intuition built on all my years of slogging through basic subjects, trekking, and working in the field, and continuously accumulating reams of knowledge about the natural world around us.’

I started imagining how I might use this to help the detectives in one of my novels solve a crime. I was thinking about storylines for my McBride and Tanner series, and then I got an idea for how I might be able to link this idea to a classic play that, while not Scottish, takes place in Scotland.

William Shakespeare wrote Macbeth around 1606. It's pretty clear that he never visited Scotland, and he didn't need to. The stage directions in his plays are sparse, with all the detail in the dialogue, and so he wouldn't have felt the need to provide a description of the Perthshire or Inverness-shire countryside for those staging his plays.

And besides, a journey from London (or from Stratford-on-Avon) to Scotland in the sixteenth century would have been a huge undertaking, and probably have taken weeks. And if you've ever watched Upstart Crow, you'll know how arduous travelling was to the bard.

But anyway. In Macbeth, a number of prophecies are made by the three infamous witches. Firstly there are the prophecies about Macbeth's rise to greatness: Thane of Cawdor and then king (no less). Macbeth, with the help of a hell of a lot of bloodshed, makes these come true.

And then there are the prophecies about Macbeth's descent from greatness, or rather what Macbeth interprets as reassurances that such a descent will never happen.

For example:

Macbeth shall never vanquish’d be until
Great Birnam Wood to high Dunsinane Hill
Shall come against him

A wood can't uproot itself and move the top of a hill 13 miles away, surely? I mean, this isn't Tolkien.

But it turns out it can. The soldiers of Macduff's army tear branches off the trees to use as camouflage, and then march on Macbeth's castle at Dunsinane, which is at the top of a hill I climbed as part of my research for the book (such dedication).

In Death and Poetry, something similar happens. Instead of the killer tearing branches off the trees at Birnam Wood (which is a beautiful place for a research walk, if not for a murder), they place soil and vegetation from Birnam Wood in the pockets of their victim, whom they then dump at the top of Dunsinane Hill.

The team don't immediately get the connection. But when they do, they realise that this isn't your normal run-of-the-mill murder (if there is such a thing). This is the work of someone who wants the police to see the Macbeth connection.

But why?

Well, that's a question that only the forensic psychologist Dr Petra McBride can answer. And a question you'll have answered too, when you read the book.