Ready to Run: A Zayn Malik AU Story

Detective Liam Payne has to protect his "daughter," Becca, who is new to London. She is no ordinary Year 11 school girl. She has secrets, dangerous secrets, which is why she was put into his care at the beginning of summer holiday. Now that the new school term is starting, he has young-looking detectives, like Niall Horan, enrolled in her school to keep an eye on her when he can't. The girl needs protection and she won't let anyone close to her.
Zayn Malik is a new music teacher to the school and quickly becomes popular with the students, but doesn't speak much of his past. He takes a quick interest in Becca after a request to stay after class to hear her demonstrate her ability to play an instrument reaches him deeply and he senses the sadness in her music. Seeing Becca push everyone away makes him determined to help her, more so when she starts to let him in.
When Payne forces Zayn's past out of him under the impression of an inappropriate relationship between him and Becca, Zayn starts getting distant from her. Not long after, Becca's past finds her in London and both her and Zayn are caught in the middle of it, against what she wanted.
Harry Styles is the head of London's mafia and underworld. He is desperate to find Becca, knowing who she really is. She could be perfect leverage or a good ally, he's not sure. So he has his top guy Louis and others helping him find her and keep others away from her.
With everything after Becca and Zayn's secrets, will they be able to get past their secrets and come together to survive?