Slickensides is the name of a farm in the High Peak district of Derbyshire, of a cheese prepared at the farm, and of the old lead mine that lies beneath it. It is also the geological term for a particular rock formation which results in the trapping of energy behind it. Such energy can be dangerously explosive when released.
All this Inspector Brunt has occasion to expound on a visit there in 1911 to investigate a reported break-in at the farm. At the same time a private detective with distinctly Holmesean characteristics (they even include a Watson!) arrives at the local inn. He is there to investigate the alleged disappearance of Barnard Brittlebank, the squire’s dissolute son. Before long he informs Squire Brittlebank that his son has left for Canada.
So it is disconcerting when young Brittlebank’s body is found in the Slickensides mine. A dense fog descends, cutting off all communication with the outside world, and Brunt is left to answer some tricky questions with no assistance beyond the evidence and that of his own sharp wits.
Although nearing retirement, Brunt is as shrewd as ever. In this beautifully realized story of a closed society three-quarters of a century ago, he demonstrates once again that he is one of the most memorable of fictional detectives, and triggers a denouement as explosive as only Slickensides can produce.