The astrologer carries a great burden of guilt for many years. He thinks that he committed a murder long ago, because he stabbed his acquaintance and then took steps to ensure that the latter would not rise again.
After stabbing the man, the astrologer pushed his unfortunate victim into a well. He imagined that his actions rendered the wounded man powerless to escape from the well.
The text tells us that the astrologer was drunk on that day. This could have played a part in his perception of the unfortunate incident. In the story, the astrologer learns a stunning truth: his victim did escape, after all. It was only the coincidental appearance of a stranger that saved his victim's life.
Of course, the astrologer had no knowledge of this. It is the main reason he believes that he committed a murder long ago. Because he feared being discovered, the astrologer ran away from his village. If he had stayed, he would have tilled the land, like his forefathers before him, and grown old in his ancestral home. The story ends with a stunning resolution: not only does the astrologer discover his innocence, he also manages to evade the clutches of his vengeful former acquaintance.