Now he breathed deeply of the wind--the smell of the sea, the scents of the land growths, strange but pleasant. So easy to relax, to drop into the soft, lulling swing of this world in which they had found no fault, no danger, no irritant. Yet, once those others had been here--the blue-suited, hairless ones he called "Baldies." And what had happened then ... or afterward?

A black head, brown shoulders, slender body, broke the sleepy slip of the waves. A shimmering mask covered the face, catching glitter-fire in the sun. Two hands freed a chin curved yet firmly set, a mouth made more for laughter than sternness, wide dark eyes. Karara Trehern of the Alii, the one-time Hawaiian god-chieftain line, was an exceedingly pretty girl.

But Ross regarded her aloofly, with a coldness which bordered on hostility, as she flipped her mask into its pocket on top of the gill-pack. Below his rocky perch she came to a halt, her feet slightly apart in the sand, an impish twist to her lips as she called mockingly:

"Why not come in? The water's fine."

"Perfect, like all the rest of this." Some of his impatience came out in the sour tone. "No luck, as usual?"

"As usual," Karara conceded. "If there ever was a civilization here, it's been gone so long we'll probably never find any traces. Why don't you just pick out a good place to set up that time-probe and try it blind?"

Ross scowled. "Because"--his patience was exaggerated to the point of insult--"we have only one peep-probe. Once it's set we can't tear it down easily for transport somewhere else, so we want to be sure there's something to look at beyond."

She began to wring the water out of her long hair. "Well, as far as we've explored ... nothing. Come yourself next time. Tino-rau and Taua aren't particular; they like company."

Putting two fingers to her mouth, Karara whistled. Twin heads popped out of the water, facing the shore and her. Projecting noses, mouths with upturned corners so they curved in a lasting pleasant grin at the mammals on the shore--the dolphin pair, mammals whose ancestors had chosen the sea, whistled back in such close counterfeit of the girl's signal that they could be an echo of her call. Years earlier their species' intelligence had surprised, almost shocked, men. Experiments, training, co-operation, had developed a tie which gave the water-limited race of mankind new eyes, ears, minds, to see, evaluate, and report concerning an element in which the bipeds were not free.

Hand in hand with that co-operation had gone other experiments. Just as the clumsy armored diving suits of the early twentieth century had allowed man to begin penetration into a weird new world, so had the frog-man equipment made him still freer in the sea. And now the gill-pack which separated the needed oxygen from the water made even that lighter burden of tanks obsolete. But there remained depths into which man could not descend, whose secrets were closed to him.