Gourmet food critics Norm and Jane Miles are just back from the Cayman Islands and enjoying a holiday weekend at their mountain cabin. In the midst of a powerful nighttime snowstorm, they begin experiencing bizarre hallucinations. Meanwhile, their daughter, Kelly, and her cocaine addicted boyfriend, Eric, are en route to the cabin, and chemistry professor Carl Maddy, a close family friend, is analyzing a small amount of a spice called "Washington's Salt," which Norm and Jane brought back from the Caymans. What Kelly and her boyfriend find when they reach the cabin is horrifying, and what Maddy discovers under his microscope sends him on a frantic, midnight, motorcycle ride in an attempt to save his friends' sanity.