Panic. He was starting to panic. To be perfectly honest, Jamie had always known that this day might come, that he might one day be nabbed by his father's enemies but this seemed too... pleasant for Death Eaters? Surely he would have been tied up, ready to be tortured, with Lily and Al and neither of them was to be seen. His wand was even right there, waiting for him.
He hesitated before grabbing it - no traps. Good - then used it to clean his glasses. "No," he insisted to the young kid who sounded... Odd, but he knew better than to make fun of the way someone talked, "I was at school. Dunno how the Death Eaters grabbed us - or why they'd take you." Of course, he didn't realize that the kid couldn't actually hear him particularly well so half of that wasn't entirely facing him as he looked around the room. His wand was raised even though he didn't really know much about curse detecting.