In a snowy wood, in Maine, in midwinter, three children make an amazing discovery. The fuselage of a light airplane is jammed among the branches. The crew, a man and a woman, are strapped lifeless and frozen in their seats. Beside the body of the woman is a package with a message scrawled on it. It reads, "GET TONI," and is followed by groups of numbers. The children take the package, meaning to report their find to their uncle and aunt. The children are staying on their run-down farm, as unwelcome guests, while their parents deal with possible financial ruin and divorce. However, the hostile atmosphere drives the children to their rooms. Thus, they open the package when they are alone. It is crammed with cash. Matters come to a head with the aunt and uncle, and the bitterly hurt children decide to leave at all costs. With nowhere else to go, they set out in Alec's old car to "Get Toni." Working out where Toni is, and who Toni is, and what the "Get" means, is the substance of the plot. It takes the children to a wild coast, a hidden cavern, underground rooms, a hi-tech submersible and a sophisticated smuggling gang. "Getting Toni" means a chilling underground test of endurance for two of the children; and capture and a desperate escape for the third. As the story reaches its climax, amid a fierce winter storm, the separated children make their own attempts at escape from the gang. It is a race against time. If they cannot get to safety in time, either the weather or the gang will kill them.