Accessory Before the Fact
An English man on a walking holiday experiences a short time in another man’s future
and struggles with the ethics of whether and how to deliver a warning to that other
man.
Although the method of time travel is fantasy, the man’s struggles with the
ethics of time travel put the story soundly in the realm of foundational science fiction.
— Michael Main
He had been an eavesdropper, and had come upon private information of a secret kind that
he had no right to make use of, even that good might come—even to save life.