Red hardcover mystery novel—lost near Park Street, Bristol

I lost my red hardcover mystery novel yesterday around 3pm, right outside Waterstones on Park Street in Bristol. It's a standard 7x9 inch Books & Magazines item with a rubbed spine, and there's a coffee ring stain on the back cover. Inside the front cover there's a small blue library sticker with the code BPL-12-AB. This gift from my grandmother means a lot to me—it's a sentimental link to her, and I'd be really grateful to get it back if anyone found it.