Assignment task: Please choose any two quotes from Blatty's The Exorcist and explore how each of them signifies significant changes or variations in his narrative based on the original events in St Louis.
And examine how Blatty's changes and choices alter the purpose and effect of his story overall.
Please explain why you selected these examples and what intrigues or concerns you about their function in the novel's narrative structure.
Finally, please use both quotes to consider why this particular story absolutely fascinated both readers and movie audiences in the early 1970s.