Book excerpt: After 19 books and 500,000 copies sold, it's the very last Hey Jack! title! Jack is chosen to be the Star of the Week at school, but he wants to be a good friend too. Can he do both? All this leaves Del grappling with some seriously curly questions. Is it okay to break the law to help a friend? How can a girl tell another girl she likes her without it ending in humiliation and heartbreak? And – the big one – is it ever truly possible to dance in public without falling over?