The Beginning of Brown James and Noel sat on the steps of their new house. It was going to be a hot day, but the boys preferred sitting outside to unpacking more boxes inside. Their mom was unpacking kitchen stuff, and the boys had grown tired of hearing her exclaim every time she unwrapped another of the teapots she hadn't seen in months.
"You'd think she'd have enough teapots by now," said James.
"Yeah," said Noel, "I don't get that excited about my Godzilla collection and that is way more interesting than any teapot."
"And I’m sorry," said James, "but I know way too much about teapots for a boy my age."
James then started listing all the things he knew about teapots. "There's the spout and the pouring angle," he began. But Noel had already tuned James out. The heat was rising and as tired as he was of his mother's teapots, he was more tired of James' complaining.
Besides, there was a raggedy old dog down the street. Noel could tell, even from far away, this was a dog that belonged to no one. Its coat was matted. It had no collar. All he could see of the dog's face was its nose sticking out. Its coat was all brown, but a dirty, grayish brown, not the deep dark warm brown that made you feel safe.
"And there's that teapot with the flowers. The brown one with the little dots all in a row," James continued on his rant, now listing all the teapots he had unwrapped for Mom. Noel continued ignoring James and watched the dog.
It was moving slowly in their general direction. It stopped at various spots along the curb to smell things. Sometimes the smelling took a very long time. Every now and then it would sit down to scratch behind its ear. Noel wondered if it was looking for something to eat.
James jabbered on and Noel began to wonder how a dog came to be in such a sad condition as this one. Did no one ever want it? Even as a puppy, was this fellow not cute enough to find a good family? Had it always been this ugly? Hadn't anyone ever been kind to it? The dog was across the street now, one house over. It seemed to be particularly attracted to mailboxes and the plants around them. To Noel's mind, it appeared that the dog was greeting each family on the street.
Noel watched the dog cross the street heading in their direction. He hadn't noticed it before, but the dog's head seemed rather large. It swung back and forth in front of its body, much like the bears Noel had seen at the zoo and on television. Noel could not see any eyes through all the matted hair. He could see gnats and flies hovering over the poor thing, waiting for it to sit down again.
It lumbered toward them. Noel noticed that James had stopped talking. He looked over at his brother. Staring at the dog, James seemed to be a bit shocked or surprised, maybe even stunned.
"What is that?" James whispered.
Instead of sniffing their mailbox and moving on like before, the dog started up the sidewalk toward the steps where they were sitting. Noel could hear the flies buzzing and see not just a few gnats, but a whole swarm around the dog. Bits of leaves and twigs hung in its hair. The dog continued toward them. Was it going to stop, wondered Noel. Should I get up and get in the house? But then, just when Noel felt a twinge of panic, the dog sat down, wagged its tail, and smiled. Noel had never seen anything like it before. It was as if the dog, flies and all, were posing for a photographer. It is going to be an interesting summer, thought Noel.

Why does Noel feel a "twinge of panic" at the end of this scene?
He has decided the dog is dangerous.
He has a bad history with dogs.
He is afraid of most animals.
He is unsure what the dog will do.