J. S. Fletcher 
Chestermarke Instinct [EPUB ebook] 

When the manager of a small bank in the English village of Scarnham failed to appear to open the bank on a Monday morning, it was assumed to be a matter of a missed train. But when the bank’s owners reported missing securities and Lady Ellersdeane’s jewels – worth a hundred thousand pounds – can’t be found, things take a more serious turn. Has the manager, formerly a pillar of honesty, absconded with the missing items, or has something more sinister occurred? When a body is found at the bottom of an abandoned lead mine, the latter seems more likely. Wallington Neale, the bank’s assistant manager, must discover whether it is a case of embezzlement or if the events the result of… The Chestermarke Instinct! (Goodreads)