Horace Danby collects rare books, and finances his hobby by safe-breaking. One day he is surprised in mid-burglary by the lady of the house, but she seems prepared to let him go in return for a small favour.
I discovered this story in a simplified version in two school anthologies, one published in the USA and one in India. Eventually I tracked down its first publication in the Scottish magazine, Chambers's Journal, Canning's only contribution to it as far as I know. It also seems to have been broadcast as a TV play in the USA by CBS in June 1953 in a series called Your Jeweler's Showcase, I presume sponsored by a jewellery chain.
Chambers's Journal, March, 1953, p. 185-187.