Complex sentence: Dazed and confused, Billy is not sure whether to buy the story or not, but in a further attempt to convince the officer of their connection, Thomas tells Billy about his two sisters as well as Agnes, whom Billy remembers from his youth.
Split into simpler sentences: Dazed and confused, Billy is not sure whether to buy the story or not. In attempting to convince the officer of their connection, Thomas tells Billy about his two sisters as well as Agnes, whom he remembers from his youth.