Clingman nodded. "Quite harmless. As harmless as the new ocean on Cassa One would be by this time to Tareegs who entered it." He paused. "We'd thought, Gordon ... as you might be thinking now ... of sending the drones back instead with a load of asteroid ice containing the inert agent. That, of course, would not have reduced its effectiveness. Nevertheless, the scheme wouldn't have worked."
"Why not?" Troy asked.
"Because the drones, in the Tareeg view, were sacred messengers. They could be used only to announce in a certain prescribed manner that the Tareeg interstellar expeditionary force had discovered a water planet and taken possession of it, again with the required ceremony, for the twin worlds. The transmission of lumps of interplanetary ice would never have fitted that picture, would, in fact, have been an immediate warning that something very much out of order had occurred.
"That Tareeg insistence on exact ritualistic procedure—essentially a defensive measure in their dealings with one another—also happened to delay our own plans here very badly. Except for it, we would have been ready at least a year ago to flood Cassa One and entrap our captors."
Troy repeated, stunned, "You would have been ready...."
"Yes, but consider what might have resulted from that over-hasty action. The Cassa system is much more readily accessible from the twin worlds than it is from Earth, and if we made some mistake with the drones, or if the Tareegs began to suspect for any other reason that their expeditionary force had met with disaster, they would be certain to establish themselves at once in a very strong manner here, leaving Earth confronted with a dangerously talented and implacable new enemy. No, we had to retain the appearance of helplessness until we had acquired an exact understanding of the manner in which the water-message must be prepared, and had discovered some substitute for the freezing effect on the lethal agent. That took an extra year."
Troy said carefully, "And during that year, as you knew would happen, another dozen or so men died very slow and painful deaths on the Tareeg execution benches. Any one of those men might have been you or I...."
"That is quite true," Clingman said. "But it was something that could not be avoided. In that time, we did learn the necessary ritual and we did find a numbing catalyst which will hold the protein agent inert until it loses its effect by being sufficiently diluted again. So now the drones have been dispatched. Long before this ship reaches Earth again, the agent will have been introduced to the twin worlds, and except for the specimens we carry on board, the Tareeg species will be extinct. It may not be a pleasant thing to have a pair of ghost worlds forever a little on our conscience—but one does not have to fight uncertain wars with ghosts."
Troy studied him in silence for some seconds.