The Loner is the third in the Polvellan Mysteries, a warm-hearted series set in beautiful Cornwall.

When Jess Trevanion goes to deliver some plants to John Preece, a reclusive neighbour in Polvellan village, she is shocked and saddened to find him dead. When talk turns to the funeral arrangements, Jess's sadness becomes resolve when she realises that, like herself, very few people knew the real John Preece – although he'd lived in the village for many years, his background is a mystery. Jess uses her investigative skills to research John's family, and is surprised and horrified by what she finds out.

Meanwhile, Jess also discovers the story behind Marigold's, a famous local venue, and her relationship with old flame Tom Peters continues to progress.