Ian Brady, born Ian Stewart, was born in Glasgow in the early 1930s. He experienced a tough childhood, starting with feelings of abandonment when his mum, unable to cope as a single parent, gave him up for adoption at just four months old, and his home, in the poverty-stricken slums of the Gorbals, was a hotbed of criminality.

In the 1950s, Ian Brady moves from his hometown of Glasgow to Manchester where he meets Myra Hindley at work. Their relationship develops with Brady expounding his views on life to her and confiding his darkest secrets. Brady and Hindley enact his sexual fantasies and make plans about committing a murder.

After killing four children, Ian Brady’s ego builds and he looks to expand his cult. Brady and Hindley lure a 17 year old lad back to their home where Brady sets about killing him. Their ‘new recruit’, David Smith is also lured to the house to help clean up the aftermath of the violent murder but instead of joining the clan, he calls the police and tells them about what he's just witnessed.