How about the reason that he's so quiet is that is that he spends all day shouting racist abuse at the Albanian family over the road and he's hoarse. She doesn't know that so she goes round to see him. She arrives five minutes before the police who are investigating all this racist shouting. He blames her and says it can't be him because he's hoarse. She gets arrested and all seems lost.
Fortunately she engages a top lawyer who manages to get the foremost expert on mysterious boys shouting racist abuse and driving themselves hoarse to testify, but on the way to the court room somebody drops a grand piano on his head and he has to go home for a lie down.
Despite that her top lawyer still manages to get her off, but as if often the case with these courtroom dramas, Godzilla escapes his volcanic prison, goes straight to the courtroom and eats everybody. And because it's really sad he eats her twice. Don't ask how, but he does.
The mysterious boy goes back to school where he gets the attention of another girl who says to her friend that she likes mysterious boys because they can't possibly ever be racist. She smiles at him and he smiles back quite racistly.