of those signals was unknown, but that was now almost be-
side the point. Any response would be inappropriate, since
not one of the five signals fitted the actual situationdespite
all the intellectual travail which had gone into tailoring them.
If no note were sent, Meikiejon would go away at the end
of 300 days. That might mean that Pullman’s “project,” what-
ever that was, would go throughbut that wouldn’t save the
colony. It would take Earth a minimum of two generations to
breed and mature another Sweeney from the artificially main-
tained ovaries of mercifully long-dead Shirley Leverault, and
it was hardly likely that Earth would even try. Earth probably.
knew more than Sweeney did about the “project”it would
be difficult to know lessand if Sweeney himself failed to
stop it, the next attempt would most likely arrive as a bomb.
Earth would stop wanting “those men” back, once it became
evident that she couldn’t get them even through so subtle a
double agent as Sweeney.
Item: chain reaction. There was, Sweeney knew, a consider-
able amount of deuterium on Ganymede, some of it locked in
the icy wastes of Neptune’s Trident, a lesser amount scat-
tered through the rocks in the form of lithium deuteride. A
fission bomb going off here would stand an excellent chance
of starting a fusion explosion which would detonate the whole
satellite. If any still-active fragment of that explosion should
hit Jupiter, only a bare 665,000 miles away now, that. planet
would be quite large enough to sustain a Beth~ or carbon