Why did the author spend several chapters having his hero tour every inch of Plum Island when in the end the Gordons' work there had little to do with the plot?

Compare Emma and Beth. Who do you think would have been a good life partner for John Corey?

Do you think John Corey acted correctly in his pursuit of Tobin? Did he have the right to disregard law in this pursuit? Why or why not? Is it possible Tobin would have escaped justice if John had not injured him?

What do you think Stevens did with the treasure? Was he telling the truth when he said he had it or do you think the Gordons hid it somewhere else?

Why does John Corey need to prove to himself that he is still a strong detective? Isn't his long career proof of that already...