Complex sentence: Tris Prior is shocked by the video released to the public at the end of the raid on Erudite headquarters that told the truth about the faction system and revealed that the Divergent are needed outside the borders of the city.
Split into simpler sentences: Tris Prior is shocked by the video released to the public at the end of the raid on Erudite headquarters. The video revealed the truth about the faction system and announced that the Divergent are needed outside the borders of the city.