Something in the Water by Charlotte MacLeod
There's definitely something in the water at the Maine resort where Peter Shandy is staying on a quest to find some rare lupins. When he witnesses a sudden and suspicious death over dinner, and then stumbles on some extraordinary pain6ngs, that 'something' could be good or bad...There is no shortage of people with a motive for killing Jasper Flodge, who seems to have been the most hated man in Maine; but no one is admitting to being the creator of the mysteriously unsigned paintings.