After Absalom’s servants left, both men came out of the cistern and went and told King David. “Leave right away,” they told David. “Cross the river quickly because this is what Ahithophel has advised against you. …”
When Ahithophel saw that his advice hadn’t been followed, he saddled his donkey, left, and went home to his own city. He gave instructions to his family. Then he hanged himself, died, and was buried in his father’s tomb.