"We are not the first to walk here." Sssuri had given little attention to what was stacked about him. Instead he bent over the disturbed dust in one aisle. Dalgard noted as he went to join the merman that there were gaps on those tables which ran the full length of the room, lines left in the grimy deposit of years which told of things recently moved. And then he saw what had interested Sssuri: tracks, some resembling those which his own bare feet might leave, except that there were only three toes! "_They._" Dalgard who had been a hunter and a tracker before he was an explorer crouched for a clearer view. Yes, they were recent, yet not made today or even yesterday; there was a thin film of dust resettled in each. "Some days ago. They are not in the city now," the merman declared with certainty. "But they will come again." "How do you know that?" Sssuri's hand swept about to include the wealth around them. "They have taken some, perhaps to them the most needful. But they will not be able to resist gathering the rest. Surely they will return, perhaps not once but many times. Until--" "Until they come to stay." Dalgard was grim as he completed that sentence for the other. "That is what they will work for. This land was once under their mastery. This world was theirs before they threw it away warring among themselves. Yes, they dream of holding all once more. But"--Sssuri's yellow eyes took on some of the fire which had shone in those of the snake-devil during its last seconds of life--"that must not be so!" "If they take the land, you have the sea," Dalgard pointed out. The mermen had a means of escape. But what of his own clansmen? Large families were unknown among the Terran colonists. In the little more than a century they had been on this planet their numbers, from the forty-five survivors of the voyage, had grown to only some two hundred and fifty, of which only a hundred and twenty were old enough or young enough to fight. And for them there was no retreat or hiding place. "We do not go back to the depths!" There was stern determination in that declaration from Sssuri. His tribe had been long hunted, and it wasn't until they had made a loose alliance with the Terran colonists that they had dared to leave the dangerous ocean depths, where they were the prey of monsters more ferocious and cunning than any snake-devil, to house their families in the coast caves and on the small islands off-shore, to increase in numbers and develop new skills of civilization. No, knowing the stubbornness which was bred into their small, furry bodies, Dalgard did not believe that many of the sea people would willingly go back into the sunless depths. They would not surrender tamely to the rulership of the loathed race. "I don't see," Dalgard spoke aloud, half to himself, as he studied the tables closely packed, the machines standing on bases about the walls, the wealth of alien technology, "what we can do to stop them."