Margery Allingham 
Flowers for the Judge (Campion #7) 

Scandal hits the prestigious publishing house of Barnabas when one of the directors is found dead in a locked cellar.All eyes are on the other partners at the firm – cousins of the dead man with much to gain from his demise – and all rumours hint at a connection to the disappearance of another director decades earlier.Desperate to salvage their reputation, the cousins turn to Albert Campion – but will his investigations clear the Barnabas family name, or besmirch it forever?