My brother's new friend

Sarah is seventeen years old and live with her two parents and twin brother Jason in the north side of London. Her relation to her brother is good, they are like two best friends who always talking care of each other. Their close relation with the same interests doing so they also share friends, most of them anyway. Apart from Sarah's best friend Elina who Jason doesn't like so much. One day happens one thing who change Sarah's whole life, Jason found a new friend who right away capture her interest.