Kavi needs to get the next shipment of food supplies into the walled city without using the secret underground waterways and, preferably, in a way that all the Hrum can see what they're doing. Oh, and don't get caught. How does Kavi do this? He sneaks into the Hrum main camp, spikes their drinks with the book-equivalent of laxatives, steals their supplies and then drives them into the city through the front gates. This is why you don't piss offKavi
Actually, you don't piss him off because every village and town in Farsala will come to his aid and destroy you. Because everyone trusts him just that much.