When you look down at your newborn baby, you realise they were right, those smug parents you've always rolled your eyes at- you'd do literally anything for your child. To make them happy, keep them safe.

So when Joseph Carver wakes one night to find his teenage son Max scrubbing the kitchen, hands wet with blood and panic flooding his voice as he promises it was an accident, he didn't mean to do it, Joseph does the only thing he can. He helps Max bury the body.

Joseph thinks that's the end of the nightmare. Until he finds Max with stricken eyes and bloody hands once again . . .

You'd do anything for your child - even cover up a murder.

But how many times?