Connie Hendricks, 14, is an American schoolgirl, while Rudolph, also 14, is crown prince of Thulgaria--but their minds are so nearly identical that they sometimes merge: Connie (or Rudolph) seems to go to sleep while his (or her) mind becomes a guest in the other's, able to see and hear everything that goes on. While these periods of sudden unconsciousness make their families understandably nervous, and also leads to the suspicion that Rudolph is not fit for the monarchy, the phenomenon proves valuable when Rudolph is kidnapped by political opportunists and when Connie, quickly flying to Thulgaria, is able to rescue him. Once together they discover that, when they are near, each can see and hear what the other docs without falling unconscious: proximity is clearly a future necessity. Credulity is strained to the breaking point by the basic plot device (e.g., they are both bilingual); by Connie's savoir-faire in the face of CIA men, terrorists, bombs, dogs, and guns; and by the very existence of Thulgaria--even to hardened fantasy buffs, this may seem like piffle. Still, Service does keep things moving briskly, and the two protagonists have a certain charm.