"The Beast Must Die" is a crime novel written by Nicholas Blake, the pen name of the British poet and novelist Cecil Day-Lewis. First published in 1938, the story follows a grieving father, Frank Cairns, who seeks revenge against the hit-and-run driver that killed his son. He meticulously plans to kill the man he believes is responsible, leading to a tense exploration of morality and justice. The novel is notable for its intricate plot and psychological depth, as it delves into themes of vengeance and the human condition. It is also recognized for its innovative narrative style, which includes a unique twist that challenges the reader's expectations.