In a few more days, Nelsen was flying the 'copter. Then he was out on his own, watching, searching. For a couple of weeks he hangared the heli at once, after each patrol, and Nance always was there to meet him as he did so. Inevitably the evening came when he said, "We could fly out again, Nance. For an hour or two. It doesn't break any rules." Those evening rides, high over Syrtis Major, toward the setting sun, became an every other day custom, harmless in itself. A carefully kept nuclear-battery motor didn't conk; the vehicle could almost fly without guidance. It was good to look down at the blue-green shagginess, below... Familiarity bred, not contempt, but a decline of dread to the point where it became a pleasant thrill--an overtone to the process of falling in love. Otherwise, perhaps they led each other on, into incaution. Out in the lonely fastnesses of Mars they seemed to find the sort of peace and separation from danger on the hectic Earth that the settlers had sought here. "We always pass over that same hill," Nance said during one of their flights. "It must have been a beautiful little island in the ancient ocean, when there was that much water. Now it belongs to us, Frank." "It's barren--we could land," Nelsen suggested quickly. They visited the hill a dozen times safely, breaking no printed rule. But maybe they shouldn't have come so often to that same place. In life there is always a risk--which is food for a fierce soul. Frank Nelsen and Nance Codiss were fierce souls. They'd stand by the heli and look out over Syrtis, their gloved fingers entwined. If they couldn't kiss, here, through their helmets, that was merely comic pathos--another thing to laugh and be happy over. "Our wind-blown hill," Nance chuckled on that last evening. "Looking down over a culture, a history--maybe arguments, lawsuits, jokes, parties; gossip too, for all we know--disguised as a huge briar patch that makes funny noises." "Shut up--I love you," Nelsen gruffed. "Shut up yourself--it's you I love," she answered. The little sun was half sunk behind the Horizon. The 'copter was only a hundred feet away, along the hillcrest. That was when it happened. Two dull, plopping sounds came almost together. If a thinking animal can use the pressure of a confined gas to propel small missiles, is there any reason why other intelligences can't do the same? From two bottle-like pods the clusters of darts--or long, sharp thorns--were shot. Only a few of them struck their targets. Fewer, still, found puncturable areas and struck through silicone rubber and fine steelwire cloth into flesh. Penetration was not deep, but deep enough. Nance screamed. Nelsen wasn't at all sure that he didn't scream himself as the first anguish dizzied and half blinded him.