Choose an important figure from history - a politician, an activist, a criminal, an entertainer, anyone who wasn't just well known but who changed their field and the world. Imagine what the repercussions would be if someone went back into time and eliminated them, or key moments in their lives, from history. How would the world be different - politically, socially, or in some other way?

Discuss the ethics of what Esterhazy and Ruben ask Si to do in their final conversation. Were Esterhazy and Ruben correct in saying Si would have been serving the greater good if he had in fact gone back and changed the course of Cuba's history? Alternatively, were Si and Danziger correct, and the possible repercussions of changing history in that way would be too far-reaching and too dangerous? Also: examine the question of whether Esterhazy has this goal...