Despite the glare, a mixture of worry for Peter and anger he had gone out there where danger still was, Nathan was still relieved when he caught sight of his brother. Yes, he couldn't keep his adult brother locked away, but right now he still tended to see nearly all risks as unnecessary given that a vampire who could somehow come back from turning to dust was out there and knew where to find Peter.
His attention turned to Hiro and his stance and look faded a great deal a moment later, as though Nathan was suddenly conscious of appearing too hostile. In truth, he was, because even if what Peter had angrily announced about Sylar was true, the blame was still on the name of Nathan Petrelli.
"He certainly did," he said carefully, finally looking at Peter face on, uncertain what Hiro now knew and unwilling to inflame anything further. It still didn't mean he was going to just let this go so easily, but Hiro didn't need to hear that.