There were a lot of projects between the two of them, as well as Terrence's general drive to excel at quidditch. And his failure in the latter lined up with one of the former, but that hadn't been the one Zach was making the most headway on. If Ella had been in anything near a decent mood, perhaps Zach would have gone there first, to make some more plans about Fleur, so that there was good news to deliver to T. But that hadn't been an option. Plus Zach wanted to help, himself. Not just with Ella.
But as such his current topic got a one word response. There were a couple options. He could keep talking on that one, which was relatively easy to do, or he could try to think of plans for Fleur on the spot. Well, he didn't have any just right then, though he would keep thinking about that one. If he thought of anything useful, he would share it. He knew T didn't want to interact with her at all.
"The servants themselves cannot hex private the entries nearly as well as that," Zach went along in the same vein, "so it ought to catch Umbridge's eye. That they are more protected is obvious, but there are some trips and false paths to breaking them for her. Her life ought to get more frustrating." It was a little thing, really. But it was something.