Aliens-on-trial, from the author of Frameshift (p. 424), etc. When a spaceship containing nonhumanoid aliens splashes down in the Atlantic, the President's science advisor, Frank Nobilio, and astronomer Clete Calhoun are sent to make contact. The Tosok (four eyes, two mouths, one arm in front, another in back) hibernated through the 211-year voyage, but their ship was damaged entering the solar system and they need help with repairs. Then, however, Clete's body is found butchered in the dorm where the aliens are being housed. A Tosok, Hask, is arrested and charged, so Frank hires top civil-rights lawyer Dale Rice to defend him. During the trial it emerges that one of the aliens, Seltar, supposedly killed in the accident that damaged the ship, is still alive; not only that, but she's helping Hask (he did kill Clete, but only by accident) to save humanity from the other Tosok--whose paranoid orders are to wipe out Earth with the particle-beam weapon that Hask and Frank somehow must disable. A consistently plotted if not always persuasively motivated yarn, with ingeniously constructed aliens in a fairly routine courtroom melodrama.