Jenny Leask admires the miniature cinema
But the latest conundrum to hit Edinburgh is no less baffling for its lack of bloodshed - and the only clue is a connection with the fictional cop's creator.
Intricate paper sculptures are being left in Edinburgh's cultural hotspots, with no hint as to who made them.
The Filmhouse Cinema and the National Library of Scotland are the latest recipients, after the Scottish Poetry Library was gifted a model earlier in the year.
The only connection between the three artworks appears to be an appreciation of the author Ian Rankin - but he says he too is mystified by their origin.
Staff at the Filmhouse were astonished last week to find a miniature cinema cut from the pages of several books left in the box office. It included in the audience a model of Mr Rankin enjoying a bottle of Deuchars.
Meanwhile, a model of a gramophone and a coffin, carved from a copy of Rebus's last adventure, Exit Music, was left on a display case at the National Library of Scotland.
Mr Rankin told the Evening News he was as baffled as anyone: "It seems to be someone who knows about my books - Exit Music has a scene at the Poetry Library - and maybe also my personal habits (drinking Deuchars; often to be found at the Filmhouse), but otherwise I'm in the dark.
"From the photos, it looks amazing - intricate and obviously the work of many hours. All very strange and wonderful..."
All three models had similar handwritten gift tags addressed to the organisations' Twitter names. The Filmhouse model features four rows of seats cut from leather book spines, while warriors on horseback wielding bows and arrows leap from the cinema screen. The gift label reads: "For @filmhouse - a gift - In support of Libraries, Books, Words, Ideas... & All things *magic*."
The cinema's programme and marketing coordinator Jenny Leask said: "It got left at the box office counter, and no one knows who left it. When I tweeted pictures of it, Ian Rankin came back and said he thought that a similar one had been left at the poetry library and the Evening News had done a story about it."
Ms Leask hopes to get a glass case for the model so it can be displayed in the foyer for the public to enjoy, and added: "I almost don't want to find out who's done it because they obviously don't want to be found out.
"It was such a lovely thing to get."
National Library of Scotland spokesman Bryan Christie said a model had been left there last Tuesday: "It was on top of a display case outside the reading room, somebody just left it there.
"He or she has taken a hardback of Ian Rankin's Exit Music and cut the pages up and used that to make it. It's obviously not something that somebody's knocked off in ten minutes, they've spent a bit of time and thought on this and it's very intricate."
The Scottish Poetry Library's model tree was left on a table in the library in March and discovered by staff.