Navy blue hardcover mystery novel, well-loved

I lost my navy blue hardcover mystery novel yesterday around 3pm near the La Crosse Public Library on Main Street. It's a standard hardcover, about 320 pages, with a gold-embossed title on the spine and a small coffee stain on the back cover. Inside, there's a blue striped bookmark sticking out between pages 142-143. It felt like an old friend, and it has sentimental value because I picked it up for a late-night reading club and marked it with a note to myself. If anyone found it, I’d really appreciate being reunited with it.