Terrence took only a split second to appreciate that word, the tiniest of smiles at the corner of his mouth, before it was consumed by everything else. His hand closed around her smaller one, and he closed his eyes, thinking of the most remote, isolated place he knew. Then he turned on the spot, and disapparated.
When he opened his eyes, it was to a sparse forest, a long way from home. He didn't think he'd been here before, or not for a while, it was a place that he knew somewhere in his subconscious, but he didn't know or understand what his mind was doing at the moment. It had found him a place that didn't matter to him, where he could tell that there was no one within a good distance of them, definitely not within earshot. He could have double-checked that with magic, but he didn't trust himself with his wand.
Letting go of her hand, he took a few steps forward, out of a simple instinct-driven need to move. Then he stopped, closed his eyes, fists clenching at his sides as he let it all overwhelm him. There was almost something reassuring about the way it burned, always had been; something that let him know he was alive, that even he couldn't bottle up the sheer force of his own will and magical power. If he couldn't fully control himself, no one could.
Maybe if he'd been able to fully comprehend what was happening, if he'd known what his opinions were outside of the potion's influence, he would have screamed in rage. As it was, he started to laugh. Not because he was amused, but because laughing was an easier reaction than anything else: he laughed when he was hurt, laughed under torture, laughed while he fought. It had only the tiniest bit of mirth in it.
Before he even opened his eyes again, he knew that it had started. He heard the beginning crackle as the dry underbrush around them caught fire, and as he opened his eyes, the tree in front of him burst into flame. He watched it all with a dark, but almost giddy look in his eyes, tension draining from his body as it spilled out in the form of flickering, raging fire.