"What d'you mean 'if the next conjunction is _allowed_ to occur?'" interjected Seaton. "Nobody can stop it." "I am stopping it," Dunark stated quietly, grim purpose in every lineament. "That conjunction shall never occur. That is why I must have the vast quantities of salt and 'X'. We are building abutments of arenak upon the first satellite of our seventh planet, and upon our sixth planet itself. We shall cover them with plated active copper, and install chronometers to throw the switches at precisely the right moment. We have calculated the exact times, places, and magnitudes of the forces to be used. We shall throw the sixth planet some distance out of its orbit, and force the first satellite of the seventh planet clear out of that planet's influence. The two bodies whose motions we have thus changed will collide in such a way that the resultant body will meet the planet of our enemies in head-on collision, long before the next conjunction. The two bodies will be of almost equal masses, and will have opposite and approximately equal velocities; hence the resultant fused or gaseous mass will be practically without velocity and will fall directly into the fourteenth sun." "Wouldn't it be easier to destroy it with an explosive copper bomb?" "Easier, yes, but much more dangerous to the rest of our solar system. We cannot calculate exactly the effect of the collisions we are planning--but it is almost certain that an explosion of sufficient violence to destroy all life upon the planet would disturb its motion sufficiently to endanger the entire system. The way we have in mind will simply allow the planet and one satellite to drop out quietly--the other planets of the same sun will soon adjust themselves to the new conditions, and the system at large will be practically unaffected--at least, so we believe." Seaton's eyes narrowed as his thoughts turned to the quantities of copper and "X" required and to the engineering features of the project; Crane's first thought was of the mathematics involved in a computation of that magnitude and character; Dorothy's quick reaction was one of pure horror. "He can't, Dick! He mustn't! It would be too ghastly! It's outrageous--it's unthinkable--it's--it's--it's simply too horrible!" Her violet eyes flamed, and Margaret joined in: "That would be awful, Martin. Think of the destruction of a whole planet--of an entire world--with all its inhabitants! It makes me shudder, even to think of it." * * * * * Dunark leaped to his feet, ablaze. But before he could say a word, Seaton silenced him.