"It tells the story of how Bonnie Prince Charlie raised the Stuart flag in Scotland and hoped the highland clans would join him. Some did, and some didn't," he says.
"It ended with the Battle of Culloden. The prince and his men, mostly just crofters, were short of weapons and fighters, and they lost about 1200 highlanders in an hour. Then all the land was confiscated and they had the highland clearances. "It's a good story to get across to people, and this play tells it properly."
Mr McLachlan says the play has 12 scenes, involves almost 40 actors aged from four years to 70, and is narrated by Ian Bisset in a genuine Scots accent.
"There are also 12 songs of the period, including The Skye Boat Song and Loch Lomond. We've been rehearsing the songs for four months and the play for three.
"Several of us wrote it - Alec Caulder, Ian, and myself."
Mr McLachlan says he's a fifth-generation New Zealander, his forebears migrating from Scotland in 1860. He has always taken a keen interest in Scottish and his family's history.
"And I've always had a kilt," he adds.
Entry fee to the performances is by way of a gold coin donation.