The film kicks off in May 1978, presenting a chilling montage of newspaper articles detailing the mysterious disappearances of numerous individuals, alongside the grim reality of how they were subsequently discovered. In a police raid at the notorious Firefly residence, officers uncover horrific evidence: body parts stuffed inside a refrigerator and furniture fashioned from human remains. This unsettling discovery leads to an estimate that the Firefly family's gruesome body count may soar up to 75 victims or even more. Thus, the media dubs them as "The Devil's Rejects."
As dawn breaks, we are introduced to Tiny (Matthew McGrory), who is dragging a naked, mutilated body through the woods towards the Firefly's house. He soon spots a convoy of police vehicles advancing towards their home, causing Tiny to conceal himself in the trees, observing the scene unfold. The police, led by the relentless Sheriff John Quincy Wydell (William Forsythe), brother to the deceased Lieutenant George Wydell ([Tom Towles]), prepare for a violent confrontation after extensively detailing their plan.
Inside the Firefly household, Otis (Bill Moseley) is awakened from his slumber next to a corpse, while Baby (Sheri Moon Zombie) is disturbed from her sleep as Sheriff Wydell demands their surrender through a megaphone. As the police surround the house, Otis and Baby brace themselves for what promises to be a deadly standoff. Amid the chaos, Mother Firefly recalls the joy of when Baby was just an innocent child, declaring, “I love you.” They arm themselves and prepare for battle.
As the police execute a tactical breach, the ensuing gunfire is harrowing. Officers are met with deadly resistance from the Firefly family, resulting in several casualties on both sides. The action escalates until Wydell himself is shot but remains protected by his vest, intensifying his fury. The police call for tear gas, attempting to flush out the notorious family hidden amidst the chaos. Their home transforms into a battleground, teeming with violence and desperation. In a moment of sheer devastation, Rufus (Tyler Mane) falls prey to the onslaught, leading to a heart-wrenching reaction from Mother Firefly, who ultimately attempts to take her own life, only to discover her gun is empty.
While the credits roll, viewers witness Otis and Baby making their way through a secret escape route beneath the Firefly home. Meanwhile, a fleeting moment in town showcases Captain Spaulding (Sid Haig) living a double life; after a disturbing encounter culminating in a violent confrontation with a prostitute, he discovers news about the raid on his family, plunging him into a state of concern. As communication breaks down, the remaining family members scramble to rendezvous amidst mounting threats from authorities.
Through a series of manipulative and unsettling encounters, the narrative unfolds as Wydell seeks vengeance against the Firefly family, ultimately leading to explosive confrontations with various characters that highlight the overall disturbing nature of their existence. By blurring the lines between victim and villain, the film delves into themes of familial loyalty, the consequences of a life steeped in brutal crime, and the inherent chaos that follows the devilish trio.
As the story nears its conclusion, the devastating climax peaks with fierce violence, bringing an end to the family's chaotic spree. In a heart-stopping moment, they confront law enforcement head-on, resulting in an explosive finale that encapsulates the brutal legacy of The Devil's Rejects. Throughout their journey, the essence of family—however twisted—remains a driving force, leaving a haunting impression long after the credits conclude.
