Complex sentence: While the authorities are content with believing that Heston was Shivers, Lynn is unconvinced, but decides to go out on a date to a theatre with Tuck anyway, to celebrate being paid $100,000 for the painting she was hired to do.
Split into simpler sentences: While the authorities are content with believing that Heston was Shivers, Lynn is unconvinced. Nevertheless, she decides to go out on a date to a theatre with Tuck to celebrate being paid $100,000 for the painting she was hired to do.