Complex sentence: After spending the night in a motel, Al picks up another hitchhiker, Vera (Ann Savage) (a femme fatale), who had earlier ridden with Haskell and threatens to turn him in for murdering the stranger unless he gives her all the money.
Split into simpler sentences: After spending the night in a motel, Al picks up another hitchhiker. As it happens, Vera (Ann Savage) (a femme fatale) had earlier ridden with Haskell and threatens to turn Al in for murdering Haskell unless he gives her all the money.