Lucky Starr and the Big Sun of Mercury by Isaac Asimov

being was a source of heat. Occasionally an isolated miner might have been trapped. Paralyzed with sudden cold and terror, he would be unable to call for help. Minutes later his power unit would be too low to make a radio call possible in any case. Still later, he would be dead, a frozen relic.
    Cook's mad story of the deaths in the mines made sense.
    All this passed through Bigman's mind almost in one flash while he remained unmoving, still struggling with a sense of stunned amazement at the sudden new turn of events.
    Urteil's voice was somewhere between a moan and a harsh gasp. "I-can't… Help me-help- : - It's cold-cold… "
    Bigman yelled, "Hold on. I'm coming."
    Gone in a moment was any thought that this man was an enemy, that moments before he had been on the point of killing Bigman in cold blood. The little Martian recognized but one thing; here was a man, helpless in the grip of something nonhuman.
    Since man had first left Earth and ventured into the dangers and mysteries of outer space, there had grown up a stern, unwritten law. Human feuds must be forgotten when man faced the common enemy, the non-human and inhuman forces of the other worlds.
    It might be that not everyone adhered to that law, but Bigman did.
    He was at Urteil's side in a bound, tearing at his arm.
    Urteil mumbled, "Help me… "
    Bigman grasped at the blaster Urteil still held, trying to avoid the tentacle that encircled Urteil's clutching fist. Bigman noted absently that the tentacle didn't curve smoothly like a snake would. It bent in sections as though arranged in numerous stiff segments hinged together.
    Bigman's other hand, groping for purchase on Ur-teil's suit, made momentary contact with one of the tentacles and sprang away reflectively. The cold was an icy shaft, penetrating and burning his hand.
    Whatever method the creatures had of withdrawing heat, it was like nothing he had ever heard of.
    Bigman yanked desperately at the blaster, heaving and wrenching. He did not notice at first the alien touch on his back, then-iciness lay over him and did not go away. When he tried to jump away he found he could not. A tentacle had reached out for and embraced him.
    The two men might have grown together, so firmly were they bound.
    The physical pain of the cold grew, and Bigman wrenched at the blaster like a man possessed. Was it giving?
    Urteil's voice startled him as it murmured, "No use… "
    Urteil staggered and then, slowly, under the weak pull of Mercury's gravity, he toppled over to one side, carrying Bigman with him.
    Bigman's body was numb. It was losing sensation. He could scarcely tell whether he was still holding the muzzle of the blaster or not. If he was, was it yielding to his wild, sidewise wrenches, or was it a last gasp of wishful thinking?
    His suit-light was dimming as his power-unit drained much of its energy into the voracious power-sucking ropes.
    Death by freezing could not be far away.
    Lucky, having left Bigman in the mines of Mercury, and having changed to an inso-suit in the quiet of the hangared
Shooting Starr,
stepped out onto the surface of Mercury and turned his face toward the "white ghost of the Sun."
    For long minutes he stood motionless, taking in once again the milky luminescence of the Sun's corona.
    Absently, as he watched, he flexed his smoothly-muscled limbs one at a time. The inso-suit worked more smoothly than an ordinary space-suit. That, combined with its lightness, lent it an unusual sensation of not being there altogether. In an environment obviously airless, it was disconcerting, but Lucky brushed aside any feeling of uneasiness he might have had and surveyed the sky.
    The stars were as numerous and brilliant as in open space, and he paid them little attention. It was something else he wanted to see. It was two days now, standard Earth time, since he had last seen these skies. In two days, Mercury had moved one forty-fourth of the way along its orbit around the Sun. That meant over eight degrees of