Complex sentence: During the briefing Chloe gets a call from Jack and admits that the reason Jack was calling her was that he wanted to trade the Russian bomb's circuit board to the Chinese in exchange for Audrey Raines.
Split into simpler sentences: During the briefing Chloe gets a call from Jack. Chloe later admits to him that the reason Jack was calling her was that he wants to trade the Russian bomb's circuit board to the Chinese in exchange for Audrey Raines.