The book which provokes the most spark from students is book 9, the Embassies to Achilles. If time constraints dictate that only one book be read, this is probably the one to go with.
At first, students may feel a straight-forward reaction of antipathy to Achilles. What a jerk, refusing to help his comrades!
However, over the course of the discussion, they begin to defend Achilles. They point out the public nature of the slight, and the clandestine nature of the offer to make amends. Is taking a bribe honorable? And isn't Agamemnon's offer just a huge bribe without an apology attached? Isn't the very magnitude of the bribe an implied swipe at Achilles' honor? It implies that his grievance is all about the prizes.
By the end of the discussion, while they may not be defending Achilles' choice, students may come to have much more understanding of the reasons that he rejects Agamemnon's offer.
