"They may be contraterrene."
"Seetee?"
Linus Brein nodded. "In which case from both sides we must watch our
steps. Get involved with a seetee race the wrong way and you have two
cultures with absolutely nothing in common but a life-factor, busy
tossing chunks of their own kind of matter at one another in a fight
to exterminate. So before either of you start making half-baked plans,
you'd better get your heads together and plan something that sounds
reasonable to the Big Boss. Right?"