Even as the Ring is about to begin its journey to Mordor, the traitor Saruman moves against Rohan. His army of orcs and Dunlendings battle the Rohirrim under Theoden's heir Theodred at the Isen River; they defeat the Riders, but are not able to cross the Isen.
The price for holding it is high, though, for Theodred is slain in the battle. His death leaves the Rohirrim wholly in the hands of his bewitched father, who is under the sway of Saruman's servant Wormtongue.
Rohan seems ready to fall.