Exit the Milkman
When Jim Feldtster, the head of the dairy dept. at a small, New England, agricultural college disappears under mysterious circumstances, his unpleasant wife rouses her neighbor, Professor Peter Shandy, in the middle of the night. Shandy dismisses her pleas for help as attention-seekkng hystrionics.
When Feldster still hasn't turned up to teach his classes the next day, Shandy has second thoughts, and regrets being so dismissive the night before.
After Peter and Helen Shandy's friend, Catriona McBogle, gets lost on a rarely-used backroad and finds Feldster strapped into a wrecked car and apparently suffering from amnesia, the mystery only deepens.
The mystery becomes even more profound when Feldster's unpleasant wife is found dead in their immaculate house.
This was an entertaining read. Among the cozies I've read, I'd probably rate it somewhere in the middle - not the worst by any means, but certanly not the best.