P. P. C. (audiobook)

Mary Langhorne, young, beautiful, wealthy and but recently married to Senator Ваггу Langhorne, was found murdered in a parked taxi not far from her father's home. While the police were busily engaged in searching out the murderer, Carl Ashby, a former lover of Mary’s, was poisoned. The second murder, instead of complicating matters, made it easier for investigators and guided by the letters P.P.C., which cropped up in unlikely places, they solved the mystery. - Summary by Book Review Digest, H.W. Wilson Company, 1928