She takes matters into her own hands by posing as a novelist to ingratiate herself into the family of the man whom she believes to be responsible for her son's death.
[6] Following the death of her son in a hit and run, all Frances Cairnes wants is to hunt down and kill the person she believes is responsible.
Meantime, the new police inspector in the area has found out that his predecessor didn't do a thorough job with the original investigation, and is seeking answers himself.
Many of the scenes were filmed in the West Isle of Wight AONB, including Compton Farm, where adjacent scenes of the ‘island’ and the UK mainland were filmed at opposite ends of the same farm complex.
The website's critical consensus reads, "Cush Jumbo and Jared Harris make for thrilling combatants in The Beast Must Die, a coiled potboiler that excels with deft performances and rich atmosphere.