What turnaround occurs regarding Pilkington and Frederick?

In Chapter Eight, Napoleon negotiates with Pilkington and Frederick for the lumber. He negotiates, makes a deal, and then negotiates again. At first, he has an agreement with Frederick. When Napoleon hears that Frederick plans to invade the farm, he makes an agreement with Pilkington, only to break that agreement as well. Napoleon becomes well-known for playing one side against the other.