Bouli Lanners’ picturesque setting makes room for a lonely woman to take advantage of memory loss and kid the victim they had been lovers

‘Have you guys seen Jason Bourne?” asks Brian (Andrew Still), a farm labourer in the Outer Hebrides, near the start of Nobody Has to Know. “It’s exactly the same kind of set-up!” How droll of the writer-director Bouli Lanners to invoke that breakneck action franchise when his own film could scarcely be more different, save for a plot involving memory loss. The closest thing here to an action set-piece occurs when an estate agent is tardy returning to the office, leaving her colleague to take a later-than-usual lunch break.

If this isn’t a film to set the heart racing, it doesn’t leave that organ entirely untroubled; with his script’s echoes of 40s weepie Random Harvest, Lanners is aiming for similar status. The...