My mom gave this to me while visiting her in June 2023. My grandmother wrote her name inside twice, which means she read it at least twice.

Subinspector Dick Martin (about to retire due to an inheritance) is sent to bring in an accomplished safe (or other lock) cracker, who tells him he didn't do the bank job he was suspected of because he had been elsewhere at the time, opening or trying to open the toughest locks he had ever faced --an alibi which is in fact confirmed, as far as his being elsewhere is concerned, and Martin gets very interested in the locks. ( )

I thoroughly enjoyed this book even though I had solved the mystery 2/3 of the way through the story. The book reads like a Saturday matinee serial with quick chapters, lots of action and cliff hangers. The romance at the end feels tacked on. There is no reason for the detective and the librarian to fall for each other! ( )

This is a real thriller of the old school. Dick Martin is a Sub-Inspector of Police at Scotland Yard who intends shortly to leave the force. Instead he becomes involved in the case of 'The Door With Seven Locks' and meets the girl he eventually marries. Along the way we encounter a vivisectionist who has started to experiment on humans. There are secret passages and lumbering creatures with blood-stained hands and much more besides.
Edgar Wallace is one of my favorite authors and one which I always get great pleasure in re-reading. This particular book is also one of several which I return to time after time. ( )