Co-written and produced by Guillermo del Toro, which 2010 horror film features a young girl who moves into a Gothic mansion and unleashes ancient, malevolent creatures from a sealed fireplace?

The 2010 horror film co-written and produced by Guillermo del Toro, featuring a young girl who moves into a Gothic mansion and accidentally frees ancient, malevolent creatures from a sealed fireplace, is *Don't Be Afraid of the Dark (Review)*. This chilling tale centers on eight-year-old Sally Hurst, portrayed by Bailee Madison, who is sent to live with her father and his girlfriend in the sprawling, eerie Blackwood Manor. Her innocent exploration of the old house leads her to uncover a hidden basement and a mysterious, sealed ash pit within a fireplace, from which she unwittingly unleashes tiny, sinister beings with a craving for teeth.

Guillermo del Toro's involvement as both co-writer and producer brought his signature dark fantasy aesthetic to the project. The film is a remake of a 1973 made-for-television movie, which del Toro himself has cited as one of the scariest films he experienced in his youth. While del Toro initially planned to direct, his commitments to "The Hobbit" led him to hand the directorial reins to Troy Nixey, a comic book artist making his feature film debut. However, del Toro remained deeply involved in shaping the narrative and the creatures, drawing inspiration from Welsh author Arthur Machen's darker interpretations of fairy lore, envisioning them not as benevolent sprites but as ancient, malevolent entities.

The design of these menacing creatures, inspired by mole rats, contributes significantly to the film's unsettling atmosphere. The story cleverly plays on the classic gothic horror trope of a child being the first to perceive supernatural (Review) threats, only to be dismissed by disbelieving adults. This dynamic, coupled with the film's emphasis on practical effects and a relentless sense of dread, makes for a truly unsettling experience. Despite being set in Rhode Island, the entire production was filmed in Australia, adding another layer of interesting trivia to this atmospheric horror flick.