Peter Mullan brings his formidable presence to this quirky dramedy from first-time feature director Sean Robert Dunn: he is angry and weary, disillusioned but kind-hearted, someone who got his feelings hurt a long time ago … but wouldn’t dream of making a fuss about it.

It’s Mullan who gives weight and flavour to a film that might otherwise be a bit watery and unsure quite how sharp a sting it wants to deliver.

Kenneth (played by Mullan) is a cantankerous local historian and widower in the fictional Scottish town of Aberloch, obsessed with the memory of his obscure ancestor Sir Douglas Weatherford, an unscrupulous 18th-century landowner and amateur surgeon given to vivisectional experiments on the lower orders. Sir Douglas’s writings on the importance of rational self-interest have caused him to be described by his descendant as a lost hero of the Scottish enlightenment: a mix of David Hume, Adam Smith, Dr Livingstone and Walter Scott.

Kenneth embarrassingly dresses up in wig and knee breeches as Sir Douglas Weatherford to give excruciating lectures about his hero to uncomprehending tourists. But then a low-rent Game of Thrones-style TV show starts filming in the locality. The tourist centre where Kenneth is employed eagerly throws away all its boring Sir Douglas Weatherford exhibits, repurposes itself as a fan hub and makes Kenneth dress up as one of the show’s silly characters. Kenneth is a powder keg of emotion ready to blow and what makes it worse is that Sir Douglas’s ghost is lurking about the place, full of contempt for his ridiculous and pathetic descendant.

I could have done with a lot more of Sir Douglas himself, whose dyspeptic speech at the very beginning is very funny: but that keynote of scabrous satire that he appears to introduce is overtaken by bittersweet sadness as Kenneth takes centre stage. It’s a tender and very sympathetic performance from Mullan.