In the first two books in the Coffeehouse Mysteries, the action is set in cosmopolitan New York City. This story takes a summer break: Claire Cosi is helping a friend get his (coffee-centered!) restaurant started in the Hamptons, at the end of ritzy Long Island, and living in David's house (mansion, more like) along with her daughter and boss/ex-mother-in-law. During the Fourth of July party, one of the restaurant employees is shot to death... and Claire is certain David was the target. The police don't agree. Naturally, she feels compelled to find out the truth.
That's a recipe for a standard cozy mystery, but this one does a particularly good job. First, Coyle makes Claire completely believeable. Other than the initial premise (*I* never had a customer offer me the opportunity to spend the summer in the Hamptons), the protagonist makes sensible deductions, and has normal reactions to stress (such as an ongoing spat with her daughter). The pacing is done well enough that I kept turning pages, and I gulped down the book in a few short days. Best of all, I really didn't know who the murderer was until it was revealed.
The coffee recipes (including an 8-layer fancy coffee drink and espresso-boosted brownies) and coffee knowledge (a long essay on matching high end Brazillian coffee with almonds and figs) are well integrated into the story, too. You learn a lot, without feeling as though Claire stepped out of character and up to a podium. It's also more than "basics" in coffee knowledge; I did learn quite a bit (and I'm going to seek out that Brazillian coffee she mentioned).
I got just what a wanted from a cozy mystery story: entertainment, escape, a not-too-easy puzzle to solve, and enough knowledge to make me feel that I'd learned something new. I enjoyed it. I think you will, too.