This haftarah opens with Saul confirmed as king at Gilgal, and Samuel then addressing the assembled nation directly, reminding them that he has led them from his youth into old age and asking publicly whether he has ever wronged anyone, taken an ox or a donkey, defrauded or oppressed anyone, or accepted a bribe to look the other way, a public accounting the people themselves confirm has never happened.
Samuel then reviews the nation's history, from the descent into Egypt through the judges God repeatedly raised up to deliver them whenever they were oppressed, before addressing the people's more recent demand for a king, a request Samuel treats as itself a kind of rejection of God's own direct rule over them even as he accepts that Saul has now been given to them.
The haftarah closes with Samuel calling on God to send thunder and rain during the wheat harvest, an unusual and threatening sign at that season, to demonstrate the seriousness of the people's wrongdoing in requesting a king, and once the sign occurs exactly as promised and the people express fear and repentance, Samuel reassures them that God will not abandon His people for the sake of His own great name.
The unusual sign of thunder and rain during the dry wheat harvest season is itself worth noting, since such weather at that time of year would have been recognized immediately by the assembled farmers as abnormal, giving Samuel's warning a vivid, weather based proof no one present could easily dismiss or explain away.