Title: Night's Cloak
Description: >>*"I've got to hurry," Bobby said. "Mr Weston has been found dead from a knife-wound in his study."*

>It's not easy for a county police Inspector to handle prominent local citizens diplomatically, while getting on with the real work of crime detection. But it's particularly hard when Bobby Owen finds himself the victim of a sinister swindle worked by a millionaire business executive. Not to mention the machinations of a radical political movement, a secretary with a puzzling alibi, and a young scientist-inventor, willing to do anything, even murder, to put his schemes into action...
>*Night's Cloak* was first published in 1944, the nineteenth of the Bobby Owen mysteries, a series eventually including thirty-five novels.