Anthony Gilbert 
Death Wears a Mask [EPUB ebook] 

May Forbes came four nights a week to feed the wild cats on Broomstick Common. That was how she happened to glimpse a masked man with a spade — and she’s now in fear for her life. Classic crime from one of the greats of the Detection Club May leaves the common and ends up at the Mettlesome Horse, where irascible lawyer, Arthur Crook, is drinking at the bar. So when the body of eighteen-year-old Linda Myers is found buried on the Common, Crook discovers a number of people who might want the girl dead. Then May Forbes leaves for work one lunchtime and does not reappear . . .