--_whatever-it-was?_ Lisa, in snatches, told Johnny as much as she had been able to figure out, with Thad’s help and Phil’s, about the growth and differentiation of the Mars-bugs. The bubbling vat was a sort of brain-center. It extended nerve-like networks to all other colonies of bugs. Here on the Moon, where zealous “jailors” fed and tended the “brain,” the network was just a sort of habit; on Mars, it served the vital function of connecting the water-holders, the oxygen-makers, the perceptors and proprioceptors and nutriment-synthesizers. The adaptation-or-mutation puzzler which had first caught the attention of the Dome scientists was not too different in nature from the sort of “instinctive” decision that sets the sex and functions of each new-made egg in an ant colony. All genes for each caste are present at birth; the environment of the particular cell determines the final role of the member. And the choice of environment for that cell? With a functioning conscious brain, it was much easier to understand in the--Martian? Moon-Martian? _The friend_, was the way Lee thought of it--than it was in an ant colony. She was telling him how Phil had forced her to recognize and experiment with the _psi_ effects, when the call came. It came on the radio--but that was one minute after they had reversed direction, and started back toward the other half-track. It came first in Lee’s awareness. In the middle of a sentence, she broke off, and at the same instant, in the wordless sentence of love she was “speaking”, she stopped to say, _They’re out of gas_. Later, John realized that if she’d said it aloud, he _still_ would have doubted. But in the inner dialogue there was no space for doubt or disbelief. He heard it, knew it, and acted on it, long seconds before they had switched on and warmed up their radio set, to call for help. And by that time, he’d had the next thought. He told Bourgnese, on the radio, that they were on their way, and asked them to stay tuned in. Then he switched off and started to ask Lee if she would try something--then knew she already knew, and before he could tell her exactly what it was he wanted, felt the opening channel between his own mind and the--_friend_--and switched on the set again. “Bourgnese?” “Right here.” “Listen, this might be just for laughs, but give your buggy a try again, will you?” “Tonight I’ll try anything, man,” Thad said, and then, “She won’t catch, John. We’re bone dry.” “Forget the starter. Listen--just get in gear and _drive_. I mean--damn it, this sounds nuts. _Pretend_ you’ve got gas. Like, try it once, okay?” “What can I lose?” A moment’s wait, and an exclamation--hardly more than a _whoosh_ of air, but it contained all the bafflement, delight, suspicion, excitement, and fascination that gave them the answer. Then, very calmly: “Nice going, John. We’ll make it back, I guess.” The new world of collaboration had started. EPILOGUE