In a fantastical world infused with elements of horror and steampunk, the once vibrant village of Malaria faces a dire transformation. After a devastating climate shift, farming collapses, plunging its citizens into poverty. The newly appointed ruler, King Malbert (Jay Leno), proposes a dark solution: establishing a thriving market for malevolent inventions that would enrich evil scientists while bringing chaos to the land. Those unfortunate enough to be born disfigured are condemned to a life as "Igors," cruelly branded as ignorant and servile.
Enter one particularly astute Igor, John Cusack]( /actor/john-cusack), who defies the stereotypes associated with his kind. Though he is often dismissed by his master, Dr. Glickenstein (John Cleese), Igor possesses a remarkable scientific intellect. In a secret endeavor, he resurrects a sarcastic rabbit named Scamper (Steve Buscemi]( /actor/steve-buscemi)) after the creature meets a tragic end, breathing life into him once more—and making him immortal. He also revives the brain of a man named Brian, placing it into a robotic life-support system dubbed Brain (ean Hayes).
As Dr. Glickenstein prepares for the prestigious Evil Scientists Fair with a dubious rocket invention, tragedy strikes, leading to his untimely death during a test run. Seizing the opportunity to reshape his destiny, Igor keeps the news of his master's demise hidden and decides to enter the Fair himself. He constructs a massive creature from human remains, placing the Evil Bone—the essence of pure evil—inside her finger. However, when Igor breathes life into her, he discovers that she is not the monstrous being he intended but rather gentle and kind. Mistakenly, she mispronounces the word "evil," adopting the name Eva (voiced by [Molly Shannon).
Determined to instill an evil persona in Eva, Igor rushes her to the "Brain-Wash," a place meant to fill her mind with terror. A mishap sees Brain accidentally switch channels, resulting in Eva developing a sweet disposition reminiscent of a beloved Hollywood star. Igor cleverly convinces her that the Fair is an audition for the role of Annie in the famous musical, gaining her trust in the process. As they prepare, a bond forms between them, and Eva begins to support Igor's desire to be seen differently.
Meanwhile, the formidable Dr. Schadenfreude (Eddie Izzard) looms large, having won the previous seventeen Evil Scientists Fairs yet failing to gain the king's favor. When he learns of Dr. Glickenstein's demise and Igor's creation, he makes several desperate attempts to claim Eva for himself, including a failed carriage chase and a hopeful negotiation. Igor narrowly avoids being ensnared in Schadenfreude's web of duplicity.
As emotional stakes rise, Eva grapples with her self-worth when interrogated by Dr. Glickenstein's former assistant, Heidi. Eva’s perception of herself takes a hit, leading to a heartbreaking misunderstanding when she spies Igor sharing a kiss with Heidi, who is later revealed to be Dr. Schadenfreude's disguised girlfriend, Jaclyn (Jennifer Coolidge). Accused of deception, Igor faces the wrath of the King, who disposes of him in a dark trap.
In a moment of desperation, Eva is swayed by Dr. Schadenfreude, who, with a malicious intent, reactivates her Evil Bone, transforming her into a fierce creature. Meanwhile, Scamper and Brain embark on a daring mission to rescue Igor. As they navigate back to the Fair, Igor unveils a shocking truth: the perpetual darkness plaguing Malaria stems from a weather-controlling device hidden in the King's castle. Realizing that the King is the true orchestrator of their troubles, Igor races to the arena, confronting Eva amidst the chaos.
He passionately asserts that every being holds the power of choice regarding their inner Evil Bone. In a redemptive moment, Eva overcomes her inner turmoil, forgiving Igor. With the sun shining brightly over Malaria once more, thanks to Scamper and Brain neutralizing the weather device, the King is unveiled as a charlatan.
Thus, Igor is celebrated as the new King. Dr. Schadenfreude's reign ends quickly as he loses his influence and standing. The once daunting Evil Scientists Fair undergoes a remarkable transformation into a yearly celebration of musical theater, with Eva at its heart, heralding a new era where all Igors are embraced as equals in Malaria.
