Terrence grinned. He wouldn't have minded semi-maniacal laughter at all; hell, he would surely be laughing soon enough, once they were actually in the process of doing rather than just planning. The only time he hadn't laughed in the middle of violence had been when he'd killed his parents, for quite a few reasons. Usually he laughed even when he was the one being hurt - the more pain he was in, the more he wanted to laugh about it.
Semi-maniacal? No, probably entirely maniacal. So at least Fletcher was in good company, if he was worrying about that.
And there was the park, that he had remembered from - he couldn't remember when. There were quite a few Muggles in it, distinguished by their clothing, including a few children on the swings. Would Fletcher consider those fair game as well? Terrence wasn't sure, but he didn't think he cared enough to object if the answer was yes.
"I'll put up some wards around the park, you get started on painting, yeah?" he said, reaching over to give Fletcher a companionable pat on the shoulder. "Have fun. Go crazy."