Task: Question Answering
Input (English): Passage: A group of young vigilantes seeking revenge for a sexual betrayal fall far from grace. When the truth is out, they find themselves on the dark side of justice.

It becomes a case study in how people handle themselves in a situation that goes awry. It's an essay in the consequences of ill-considered actions and how people manage themselves in a space they're entirely ill-equipped to handle.

Music teacher Bernard is attacked at his home in isolated bushland by five young people masked and dressed in black. The group have just attended the funeral of Cate's (Kestie Morassi) sister Alice, and they've come to kill Bernard, whom they blame for the girl's death as he had an affair with her when she was sixteen, and now, three years later she's taken her own life. Alice's boyfriend, Nick, is the lead agitator; Alice's best friend, Natalie, has persuaded her boyfriend, Anthony, to steal sleeping pills from his father's doctors surgery to make it look as though Bernard has committed suicide. It all however goes horribly wrong when their attempt fails and their victim fights for his life.
In the aftermath, questions are raised about the true nature of the events leading up to the botched attack. As lies and secrets are revealed, the dynamic of the once-tight group shifts as the friends begin to question each other's motives. As they move closer to the truth, the weight of their quest for justice drives them to a place of no return. 
Question: Who was 16 when she had an affair?
Output (English): Alice.