Pearls Before Swine (Albert Campion Mystery, #12)

Albert Campion returns from three years’ work for the War Office in Europe to find that Lugg, his manservant, has brought him an unusual gift from Edna, Dowager Marchioness of Carados: the black silk nightdress-clad body of a dead woman, an apparent suicide, found in her son's bed the night before his wedding.

All the books from Albert Campion series are standalone titles and can be read in any order.