Suddenly there was an intrusion into this scene of celebration. From a side street into the main square which Scott and Ylia were now going through there came a knot of people. They came on slowly, about a dozen of them, their steady progress in contrast to the aimless, carefree motions of the rest. Their faces were serious, and the group held both Martians and Earthmen. They were young-old faces, young in age but old in their apparent contempt for the scene all round them. The group remained close together, not costumed, and when a reveler pulled at the sleeve of one in invitation to join a chain dance, he was pushed away brusquely, almost angrily. When the group reached a well-lighted position near the center of the square, its members formed themselves into a tight circle. They pulled signs from beneath their tunics and thrust them up, then began moving in a shuffling lockstep, chanting discordantly. They were pickets--serious, almost fanatic young men of two planets, bound together in their cause. Their signs read: "Down with the Earth Imperialists," "Democracy, Not Mockery," "What are you Celebrating--Colonization?" and so on. They chanted the same things, out of unison, so that their voices created a nerve-tingling atmosphere of unrest. They shouted defiantly, yet not looking anywhere but at the neck of the man directly ahead in the revolving picket line. "Reds Picket Landing Day Fete," Scott said to himself, thinking in headline terms. There was tension now among the celebrants in this part of the square. This was not a time for problems, or for thinking about them, and those who had gathered to have fun were being robbed of their spree. Abruptly a Martian stepped up and in a quick motion wrested a sign from one of the pickets. He ripped it up and danced on the pieces. The picket whose sign had been snatched made no protest, aside from a look of surprise and a frown. He stayed in ranks, and the circle continued to go round. Cheers went up and other revelers pressed forward. The marchers tightened their ranks and took firmer grips on their signs. The Martian who had snatched the first was now conferring with others. He motioned to a group of silently-standing musicians, and they took up a tune. The music was rousing and patriotic, and some costumed Martians went into a wild snake dance. With apparent good humor, but with telling effect, they drove into the circle of pickets and split them into two groups. In the scramble, several more signs were trampled underfoot. More revelers joined the attack and the pickets were split again, until they were widely separated and all their signs were gone. Their unity lost, they disappeared in the crowd. The musicians switched to a gayer tune and there were cheers and laughter. The Martian who had grabbed down the first sign was hoisted into the air, where he bowed his over sized head, grinning. The interruption of the fun was ended, and without violence. Scott and Ylia moved on.