Simplify the following text for a Grade 9 native English-speaking person.
Original: During a side track to the Northern Air Temple on his own , Aang is betrayed by a peasant and captured by a group of Fire Nation archers , led by Admiral Zhao ( Aasif Mandvi ) , a Fire Nation Admiral appointed by the Fire Lord .
Simplified: During a side track to the Northern Air Temple on his own , Aang is betrayed by a peasant and captured by a group of Fire Nation Yuu Yan archers , commanded by Zhao .