Complex sentence: Nadia first thinks that he will have to leave with her now but he instead shoots himself in the leg and tells her to leave as reinforcements arrive, making it appear as if Nadia shot Sayid and the other officer to escape.
Split into simpler sentences: Nadia first thinks that he will have to leave with her now but he instead shoots himself in the leg and tells her to leave as reinforcements arrive. Making it appear as if Nadia shot Sayid and the other officer to escape.