This concludes Krishna's dialog with Arjun about Dharma, Bhakti, Yoga, and the Gunas. During the course of this, Arjun is granted divine sight, and is able to catch a glimpse of Krishna's true appearance; it nearly blows his mind.
Getting back to Arjun's original question-- Does Arjun's Dharma really require him to kill his relatives and gurus? and how can this can be a good thing? It seems like a lot of Krishna's teaching is addressed to posterity, because advice to meditate more often isn't exactly going to propel Arjun into the battlefield. I think the convincing part of it for Arjun was the divine vision in which he saw his enemies rushing inexorably to their deaths. Whether he followed his Dharma, or ran away, these guys were dead men walking. So the decision to fight was a personal one. Whether he fired the arrow that killed his grandfather or not, the sin of murder would not be on his conscience.
This ends the Gita. We have only one small formality to take care of, and then finally the battle will begin-- next episode!