What is the main conflict in Amsterdam by Ian McEwan?

Molly Lane, a restaurant critic, has just died after suffering from a terminal disease that caused rapid deterioration of her physical and psychological faculties. At her funeral, her husband and former lovers have gathered at a crematorium in London to pay her their last respects. One of her former lovers is a composer named Clive Linley. Clive finds it unbearable to think of how horrible it must be to lose one's health so suddenly and he concludes that it is better to die than to suffer in the way in which Molly must have suffered just prior to her death. Clive asks his old friend, Vernon Halliday, who is also one of Molly's former lovers, to euthanize him if he should ever fall suddenly and irreparably ill. Vernon agrees to do so as long as Clive agrees to do the same for him.