Navy duvet cover set with geometric pattern

I found a navy duvet cover set with matching shams this afternoon around 3:15pm, tucked behind the back entrance of the Port Huron Public Library on Military Street in The Thumb. It's a Nautica queen-size duvet cover in soft cotton, with a crisp white geometric lattice pattern. There’s a small coffee stain in the lower corner and a tiny silver monogram A.H. stitched near the zipper. The fabric feels relatively new and clean, so I figured it probably belongs to someone who would miss it soon. If this matches your bedding, share a distinguishing detail and we can arrange a safe return.