A bunch of quirky seniors on tour around historic Scotland forms the background to this enjoyable mystery, with the Iowa group discovering that more lurks around Loch Ness than the monster.

BONNIE OF EVIDENCE brings tour guide Emily Miceli and some of her family to Edinburgh's military tattoo, escorting a charmingly curmudgeonly party who are determined to see the sights, shop and win a team game. The sport of geocaching has replaced scavenger hunting, with websites giving a GPS location of a cache and the teams of seniors doing their best to track the objects down. The city's castle and narrow closes give the first day's sport, with endless arguments which drive Emily mad.

Next the group tours the moored Royal Yacht Britannia and from there moves on to the town of Braemar, with another cache disputed over in the bar, when a small dagger, or dirk, has been found by one team who mistakenly thought it was the prize. Arguments ensue over the sides taken in the Battle of Glen Coe and some men appear in kilts, very pleased with themselves. So far, so usual... until the woman who held the dirk is found dead in bed and the dirk is missing. Loch Ness nearby could have been atmospheric enough, but their hotel owner declares that the dirk is ancient and cursed, having taken the life of a chieftain. The police allow the group to continue on their journey to the top of Scotland and a ferry to the Orkney Islands, but by now Emily is starting to think that not just the dirk but the whole trip is cursed. Then the dirk reappears - alongside another dead body....

This lively light tale from Maddy Hunter is part of her 'Passport to Peril' series, where she recreates all the things that have gone wrong on her own journeys, though we can hope she didn't meet quite so many murders. There is lots of historic background sprinkled in, and perhaps too much arguing over the relative merits of the Campbells and the McDonalds three hundred years after an act of treachery. Read BONNIE OF EVIDENCE for a modern look at Scotland, and you might even consider taking up geocaching yourself.