Simplify the following text for a Grade 6 native English-speaking person.
Original: Helm 's Deep is besieged by Saruman 's orcs , but Gandalf arrives with reinforcements , and the orcs are defeated .
Simplified: Saruman sends his army of ten thousand Uruk-hai , Orcs , and Dunland men to Helm 's Deep . The next morning Gandalf arrives with another Rohirrim army .