When is a legend, legend? Why is a myth, a myth? How old and disused must a fact be for it to be relegated to the category: Fairy tale? And why do certain facts remain incontrovertible, while others lose their validity to assume a shabby, unstable character?

Rukbat, in the Sagittarian sector, was a golden G-type star. It had five planets, plus one stray it had attracted and held in recent millennia. Its third planet was enveloped by air man could breathe, boasted water he could drink, and possessed a gravity which permitted man to walk confidently erect. Men discovered it, and promptly colonized it, as they did every habitable planet they came to and then, whether callously or through collapse of empire, the colonists never discovered, and eventually forgot to ask, left the colonies to fend for themselves.

When men first settled on Rukbat’s third world, and named it Pern, they had taken little notice of the stranger-planet, swinging around its primary in a wildly erratic elliptical orbit. Within a few generations they had forgotten its existence. The desperate path the wanderer pursued brought it close to its stepsister every two hundred (Terran) years at perihelion. When the aspects were harmonious and the conjunction with its sister-planet close enough, as it often was, the indigenous life of the wanderer sought to bridge the space gap to the more temperate and hospitable planet.

It was during the frantic struggle to combat this menace dropping through Pern's skies like silver threads, that Pern's contact with the mother-planet weakened and broke. Recollections of Earth receded further from Pernese history with each successive generation until memory of their origins degenerated past legend or myth, into oblivion.

To forestall the incursions of the dreadful Threads, the Pernese, with the ingenuity of their forgotten Terran forebears, developed a highly specialized variety of a life-form indigenous to their adopted planet. Such humans as had a high empathy rating and some innate telepathic ability were trained to use and preserve this unusual animal whose ability to teleport was of great value in the fierce struggle to keep Pern bare of Threads.

The winged, tailed, and fiery-breathed dragons (named for the Earth legend they resembled), their dragonmen, a breed apart, and the menace they battled, created a whole new group of legends and myths.

Once relieved of imminent danger, Pern settled into a more comfortable way of life. The descendants of heroes fell into disfavor, as the legends fell into disrepute.

This, then, is a tale of legends disbelieved and their restoration. Yet how goes a legend? Where is myth?

LESSA WOKE, cold. Cold with more than the chill of the everlastingly clammy stone walls. Cold with the prescience of a danger stronger than the one ten full Turns ago that had then sent her, whimpering with terror, to hide in the watch-wher's odorous lair.

Rigid with concentration, Lessa lay in the straw of the redolent cheeseroom she shared as sleeping quarters with the other kitchen drudges. There was an urgency in the ominous portent unlike any other forewarning. She touched the awareness of the watch-wher, slithering on its rounds in the courtyard. It circled at the choke limit of its chain. It was restless, but oblivious to anything unusual in the predawn darkness.

Lessa curled into a tight knot of bones, hugging herself to ease the strain across her tense shoulders. Then, forcing herself to relax, muscle by muscle, joint by joint, she tried to feel what subtle menace it might be that could rouse her, yet not distress the sensitive watch-wher.

The danger was definitely not within the walls of Ruatha Hold. Nor approaching the paved perimeter without the Hold where relentless grass had forced new growth through the ancient mortar, green witness to the deterioration of the once stone-clean Hold. The danger was not advancing up the now little-used causeway from the valley, nor lurking in the craftsmen's stony holdings at the foot of the Hold's cliff. It did not scent the wind that blew from Tillek's cold shores. But still it twanged sharply through her senses, vibrating every nerve in Lessa's slender frame. Fully roused, she sought to identify it before the prescient mood dissolved. She cast outward, toward the Pass, farther than she had ever pressed. Whatever threatened was not in Ruatha… yet. Nor did it have a familiar flavor. It was not, then. Fax.

Lessa had been cautiously pleased that Fax had not shown himself at Ruatha Hold in three full Turns. The apathy of the craftsmen, the decaying farmholds, even the green-etched stones of the Hold infuriated Fax, self-styled Lord of the High Reaches, to the point where he preferred to forget the reason he had subjugated the once proud and profitable Hold.

Relentlessly compelled to identify this oppressing menace, Lessa groped in the straw for her sandals. She rose, mechanically brushing straw from matted hair, which she then twisted quickly into a rude knot at her neck.

She picked her way among the sleeping drudges, huddled together for warmth, and glided up the worn steps to the kitchen proper. The cook and his assistant lay on the long table before the great hearth, wide backs to the warmth of the banked fire, discordantly snoring. Lessa slipped across the cavernous kitchen to the stable-yard door. She opened the door just enough to permit her slight body to pass. The cobbles of the yard were icy through the thin soles of her sandals, and she shivered as the predawn air penetrated her patched garment.

The watch-wher slithered across the yard to greet her, pleading, as it always did, for release. Comfortingly, she fondled the creases of the sharp-tipped ears as it matched her stride. Glancing fondly down at the awesome head, she promised it a good rub presently. It crouched, groaning, at the end of its chain as she continued to the grooved steps that led to the rampart over the Hold's massive gate. Atop the tower, Lessa stared toward the east where the stony breasts of the Pass rose in black relief against the gathering day.

Indecisively she swung to her left, for the sense of danger issued from that direction as well. She glanced upward, her eyes drawn to the red star that had recently begun to dominate the dawn sky. As she stared, the star radiated a final ruby pulsation before its magnificence was lost in the brightness of Pern's rising sun. Incoherent fragments of tales and ballads about the dawn appearance of the red star flashed through her mind, too quickly to make sense. Moreover, her instinct told her that, though danger might come from the northeast, too, there was a greater peril to contend with from due east. Straining her eyes as if vision would bridge the gap between peril and person, she stared intently eastward. The watch-wher's thin, whistled question reached her just as the prescience waned.

Lessa sighed. She had found no answer in the dawn, only discrepant portents. She must wait. The warning had come and she had accepted it. She was used to waiting. Perversity, endurance, and guile were her other weapons, loaded with the inexhaustible patience of vengeful dedication.

Dawnlight illumined the tumbled landscape, the unplowed fields in the valley below. Dawnlight fell on twisted orchards, where the sparse herds of milchbeasts hunted stray blades of spring grass. Grass in Ruatha, Lessa mused, grew where it should not, died where it should flourish. Lessa could hardly remember now how Ruatha Valley had once looked, sweetly happy, amply productive. Before Fax came. An odd brooding smile curved lips unused to such exercise. Fax realized no profit from his conquest of Ruatha... nor would he while she, Lessa, lived. And he had not the slightest suspicion of the source of this undoing.