Simplify the following text for a Grade 10 native English-speaking person.
Original: Ethan Spaulding directed part one ( The Phoenix King ) , Giancarlo Volpe directed part two ( The Old Masters ) , and Joaquim Dos Santos directed parts three and four ( Into the Inferno + Avatar Aang ) .
Simplified: Ethan Spaulding directed part one , Giancarlo Volpe directed part two , and Joaquim Dos Santos directed parts three and four .