Besides attending the attorneys ' conference , Thompson and Acosta looked for ways in Vegas to explore the theme of the American Dream , which was the basis for the novel 's second half , which Thompson referred at the time as `` Vegas II '' . Besides attending the attorneys ' conference , Thompson and Acosta looked for ways in Vegas to explore the theme of the American Dream , which was the basis for the novel 's second half , to which Thompson referred at the time as `` Vegas II '' .