Complex sentence: Raigan's agent shows up on the set to find Curtis/Raigan has vanished--as the set is being dismantled, a teaser shows the "Arthur Curtis" script left on a table, waiting to be thrown in the trash.
Split into simpler sentences: Raigan's agent shows up on the set to find Curtis/Raigan has vanished. As the set is being dismantled, a teaser shows the "Arthur Curtis" script left on a table, waiting to be thrown in the trash.