Jamie hadn't been outside the Hogwarts grounds since his arrival just about two months prior. Seeing Diagon so empty was...eerie. It hit home how much of his world was gone, the people he'd grown up with, dated, worked with, partied with. Outside of the small group of them at the castle, it was all gone. The sombre nature of the surroundings had the effect of quieting the usual exuberance with which he would have done his job.
And, he did see this like his job. Maybe he wasn't looking for counter-curses. But, there was a certain amount of investigation and trial-and-error to working through a curse or curse chain, particularly if they were unfamiliar.
Walking into the shop, though...that hit hard. "I can't imagine what Rox must have felt walking into this," he said quietly, looking around at the emptiness that still housed so many memories from his own childhood as well as his cousin's. It seemed unnatural to walk through that door and not hear Uncle George's voice calling to him, urging him to try this latest gizmo, sure to be just the thing to give him a laugh. The first endorsement he'd ever done had been for his uncle's shop when he was five and George persuaded his parents to at least see if Jamie liked it and could tolerate the cameras before refusing all offers.
He echoed his dad's sigh -- and he was still surprised to have been asked on this trip instead of his aunt and uncle! -- and then hopped up to sit on the empty counter as he had done for most of his childhood until Uncle George declared him too big and started shooing him off. "If this were the job back home and we knew the spells were tied to the caster in some way, we'd look for sympathetic magic." He conjured his patronus, letting the stag form and nose at his shoulder before directing it around the store in search of magic similar to his dad's. "Something new I've been toying with. Only works about half the time. Still trying to get the kinks out. But, worth a shot, since it's you that hid the clues and it knows your stag so well."