Sophie is a young orphaned girl living in the orphanage of the cantankerous and abusive Mrs. Clonkers. One night, Sophie wakes up and goes to look through the window but sees a cloaked giant man blowing something through a trumpet into a bedroom window down the street; whereupon the giant notices her and snatches her to the realm of Giant Country.
Sophie, a 10-year-old girl who lives in a London orphanage, stays awake reading through the nights due to her insomnia. At 3 in the morning, or what she calls the "wikt:witching hour", she sees an elderly giant outside her window. The giant captures her and takes her into Giant Country. There, he explains that Sophie must stay with him for the rest of her life because she saw him and must not be allowed to reveal the existence of giants. He also explains that she will put herself at risk if she goes out in the open, as nine other giants inhabit Giant Country, all of whom are man-eaters and favor the taste of children.