Leland Gaunt opens a new shop in Castle Rock called Needful Things. Anyone who enters his store finds the object of his or her lifelong dreams and desires: a prized baseball card, a healing amulet. In addition to a token payment, Gaunt requests that each person perform a little "deed," usually a seemingly innocent prank played on someone else from town. These practical jokes cascade out of control and soon the entire town is doing battle with itself. Only Sheriff Alan Pangborn suspects that Gaunt is behind the population's increasingly violent behavior.

The town of Castle Rock, Maine has seen its fair share of oddities over the years, but nothing is as peculiar as the little curio shop that’s just opened for business here. Its mysterious proprietor, Leland Gaunt, seems to have something for everyone out on display at Needful Things…interesting items that run the gamut from worthless to priceless. Nothing has a price tag in this place, but everything is certainly for sale. The heart’s desire for any resident of Castle Rock can easily be found among the curiosities…in exchange for a little money and—at the specific request of Leland Gaunt—a whole lot of menace against their fellow neighbors.

Everyone in town seems willing to make a deal at Needful Things, but the devil is in the details. And no one takes heed of the little sign hanging on the wall: Caveat emptor. In other words, let the buyer beware…