When busy trainee doctor Alison Hewitt joined a dating agency in 2010, she had no idea that her actions would set in motion a terrifying chain of events that would threaten the lives of her and her family.
She thought the man she was meeting was a respectable Canadian businessman living in London called Al Amin Dhalla. At first their relationship blossomed, but soon Alison's mother Pam grew suspicious of the man who seemed to harbour many dark secrets.
Pam turned Miss Marple, hired a private investigator to find out more and soon realised that Dhalla's entire life story was based on lies. It was only when Alison finished the relationship however that the real Dhalla emerged.
The family soon found out that Dhalla - classed as a narcissistic psychopath - would stop at nothing to win Alison back.
Starting with poison pen letters, his campaign of terror soon escalated to arson, building a mobile torture chamber in his van, and eventually hiring a hit man - all while tracking Alison and her family's every move.
Five different police forces became engaged in a cat and mouse chase that saw them constantly one step behind Dhalla as he sought revenge for what he saw as the ultimate betrayal.
This is a true life crime committed in middle England, but with the plot of a Hollywood thriller.
Through exclusive access to Alison, her family and the officers involved - who say they narrowly prevented a triple murder - plus police surveillance and CCTV footage, this nail-biting film tells the frightening story of what could happen if there's a stalker at the heart of your family.