After their foster guardian, Mrs. Malone, dies, they are placed by social services in a juvenile detention home under grim, unwholesome conditions, where Tia befriends a black cat, Winkie.

The writer, a Blue Ridge Mountains resident with "a name like Caroway, or Garroway, or Hideaway" sought information on students who had "unusual aptitudes".

When a man named Lucas Deranian, claiming to be the brother of their deceased father, shows up at the detention center to take custody of them, they instinctively know he is not their uncle and has ulterior motives.

With the assistance of an inner-city Roman Catholic priest, Father O'Day, the pair run away, following the map's route leading towards the Blue Ridge Mountains.

Their flying saucer was shot down over Hungary, resulting in the deaths of all but Tony, Tia, and Uncle Bené – a non-relative, but one of their own people, who rescued the children from Soviet captivity.