While spending the summer working as an au pair girl for a couple in England, Maris discovers that the husband is a werewolf intent on blooding her and making her one, too. The Warnings by Margaret Buffie Rachel leads a lonely life with the old people she calls the Fossils until she starts to receive the Warnings, strange psychic messages that let her know of a grave threat. The Duplicate by William Sleator David finds a gadget on the beach and accidentally discovers it is a duplicator. But this device reeks havoc when the duplicate David creates an evil third David. Except for one old man and a baby, all the people of Piedmont are dead of some swift and contagious disease.
Scientists struggle to find out where the alien microbe comes from before all human life is at risk.