Complex sentence: Two of the missing men are later returned to the States, and Riley hears of two Arabs who were stoned to death out in the desert, and is convinced that they were his former Masters, trying to keep their word.
Split into simpler sentences: Two of the missing men were later returned to the States, and Riley heard of two Arabs who were stoned to death out in the desert. He was convinced that they were his former masters, trying to keep their word.