In the short story Accident, Inspector Evans is a retired CID detective who settles in "a country cottage of his dreams" in an English village. He tells his friend Captain Haydock that he recognises a fellow villager Mrs Merrowdene actually is Mrs Anthony. Mrs Anthony was put on trial for murdering her husband, but was acquitted. Haydock believes in leaving things which do not concern him well alone. However Evans has the opposite philosophy in life. "Acting on information received...." had been his motto. He had been a "very smart, wide-awake officer" who had justly won his promotion. He believes that a murderer is seldom content to stop at one crime. This is likely to be another. His suspicions deepen when he finds that Mrs Merrowdene's husband Professor Merrowdene has just taken out a life insurance which pays out to his wife on his death. Evans' challenge is not to apprehend a murderer but prevent a murder.
How this is resolved forms the main plot of the story, which has a surprise for Evans.