Red Penguin Classics mystery novel with green ribbon bookmark

I lost my red Penguin Classics edition mystery novel yesterday around 3pm. I was in York, near Waterstones on Coney Street, when I realized it wasn’t in my tote anymore. It’s a Penguin Classics edition, red cover with a green ribbon bookmark, and the spine is a little creased from travel. There’s a coffee stain on page 120 and a small dent on the bottom corner of the dust jacket. It was a gift from my grandmother, so it really means a lot to me—please help me get it back.