Harry looked at James, still smiling, trying to hear. "What?" he yelled, leaning toward James.
"Down there!" James shouted, still pointing. "He's not supposed to be here! He's a Muggle! I've seen him here before!"
Harry's face changed instantly. The smile snapped shut. Harry stood up to his full height and scanned the field. James glanced back down as well, searching for the Muggle intruder. He was sure he'd be gone and that James would be left looking like a fool, but the man was still there, staring up into the melee above. He had lowered his camera, James saw. It dangled from his right hand. James looked closer and saw that the man had bandages on his upper arm, and smaller bandages taped to two places on his face. He had gotten hurt crashing through the stained-glass window, but apparently not hurt enough to avoid coming back.
Harry was pushing past the American delegation, excusing himself politely but firmly, heading toward the stairs. James followed, trotting to keep up. Together, they traversed the stairs two by two, heading down to field level. James recognized that his dad was in full Auror mode now, not thinking, really, but letting instinct take over. There was no sense of panic or worry or anger, just businesslike purpose and unstoppability. Harry reached the field with James right behind him just as the game ended. There was a thunderous ovation and suddenly people were running onto the field. The cool down crews came out to collect the empty buckets. The teams began to come in for landings, dropping to the pitch like dandelion seeds. Cabe Ridcully strode across the center line, using his wand to summon the game balls. Undeterred, Harry walked purposefully toward the end of the field where he and James had seen the strange man, but now that they were on the pitch, they couldn't see him anymore. There were too many people moving about, too much noise and confusion. James knew that there were a hundred ways the man could already have slunk away, disappearing into the spreading shadows of the hills and woods beyond the pitch.
Harry didn't stop moving until he stood on the spot they'd seen the man standing. He turned slowly, taking in the sights from what would have been the man's perspective.
"There," he pointed. James looked and saw that his dad was pointing at the base of one of the grandstands, at the doorway leading into the Ravenclaws' holding pen. "Or there. Or there," Harry said, talking partly to James and partly to himself, indicating first the path that ran between the Hufflepuff and Slytherin grandstands and then pointing at the equipment shed. "He probably wouldn't choose the shed, since he'd know there was no back way out. At best, it's a hiding place, and he'd be looking to get away, not hide. The grandstand exit would just take him farther in. No, he'd choose the path, then. It's only been two minutes. James?"
James looked up at his dad, eyes wide. "Yeah?"
"Tell the Headmistress what we saw and have Titus meet me at the entrance to that path in five minutes. Don't run. We don't know what this is about and we don't need to cause any concern yet. Just walk fast and tell them what I said. OK?"
James nodded briskly, and then turned back the way he and his dad had come, reminding himself not to run. As he climbed the steps, pressing through the departing crowd, not even knowing yet who'd won the match, he realized how utterly gratified he was that his dad had believed him. In some small part of his mind, James had been worried that his dad would doubt him, perhaps even dismiss his concerns. But James had counted on the hope that his dad knew him better than that, that his dad would trust him. Harry had done just that, descending to the field to investigate the strange man without any question or hesitation. Of course, that was how Aurors worked. Investigate first, then ask questions if any are required. Still, James was extremely glad that his dad had trusted him enough to go after the man based solely on James' word.
Despite his relief at his dad's response, however, James was sorely disappointed that the man had gotten away so easily. Somehow, he knew that Harry and Titus would not find any sign of the man or any clue of where he'd gone. Then, James would be right back where he'd started, with nothing but the glimpse of an unknown person on the Quidditch pitch to back up his story.
Thinking that, he finally caught up to Titus Hardcastle and the rest of the group. When he gave them his messages from Harry, Titus excused himself with a word and headed briskly down the stairs, his hand in the pocket he kept his wand in. McGonagall and the Ministry officials listened to James' explanation of the man he and Harry had seen on the field, the Headmistress with a look of stern attentiveness, Ms. Sacarhina and Mr. Recreant with looks of mild puzzlement.
"You say he had some sort of camera, dear boy?" Sacarhina asked mildly.
"Yeah, I've seen them before. It makes movies. He was filming the match."
Sacarhina looked at Recreant with a strange expression that James took for disbelief. He wasn't surprised, and he didn't really care. He was more concerned that McGonagall believe him. He was about to tell her the man was the same man that he'd accidently kicked through the window, but something about the expression on Sacarhina's face made him decide to wait until they were in private.
On the way down the steps again, flanked by McGonagall, the Ministry officials, and the Alma Alerons, James finally heard the score. It turned out that Ravenclaw had won the game. James felt annoyed and deflated, but he took some comfort in knowing that at least Zane was probably having a good evening.

When they reached the path leading back to the castle, Headmistress McGonagall sidestepped out of the line.
"Professors and guests, please feel free to return to the castle on your own. I prefer to attend to this situation in person," she said briskly and turned to cross the field. James darted to follow her. When he caught up with her, she glanced down at him.
"I suppose it would be pointless for me to tell you this is no business of a first-year student," she said, apparently choosing, against her better judgment, not to send James up to the castle. "The Auror in charge being your father, he'd probably ask for you to be there, no less. One wonders how he is able to keep his head on straight without Miss Granger to reel him in."
It took James a moment to realize 'Miss Granger' was Aunt Hermione, whose last name was now Weasley. He couldn't help smiling at the thought that the Headmistress still tended to think of his dad and aunt and uncle as troublesome, if generally likeable, little kids.
By the time they reached the head of the path that cut between the Slytherin and Hufflepuff grandstands, Harry and Titus Hardcastle were coming back from their cursory examination of the area.
McGonagall spoke first, "Any sign of the intruder?"