who is going to pay

Old Master Zo wished he could beat this unfilial son to death but he did not dare to say anything. He seemed to have realized the crux of the situation, Zi Mu had signed a contract but the farm had been burned which meant that the contract which was in effect was now pressing heavily on the heads of his son and his son-in-law! 

He turned to look at Yu Dong and pretended as if he did not understand what was going on. He said, "Miss Yu, I really don't understand why are you here, if they were the ones who signed the contract and did not hand you the fruits, then you should be looking for them and not us."

In short, he was telling Yu Dong that he was not going to pay compensation or anything of the sort to her for Zi Mu and Ye Zexian.