From one of the myriad pouches at his belt he drew out a small clay jar marked by strange runes. "With this." He broke the jar's lead seal. She could see some sort of emerald green salve inside. "Give me your hands." She held them out, and he carefully spread a thin layer of salve over them. "Now, try to grip the wall."

She glared at him. Did he take her for an idiot?

"Grip the wall, Ravendas," he urged again.

She supposed she might as well discover what game he was playing. Walking to the wall, she reached out and attempted to grasp the smooth black surface. Her fingers sank into the stone. She recoiled in shock, staring at her hands. Gradually realization dawned over her.

"Where did you get this, Marnok?"

His expression was unreadable. "I have my sources."

She turned back toward the wall and dug her fingers once more into the rock. It was a strange sensation, like plunging her hands into thick, cold mud. She began pulling herself upward. Why should she wait for the mage, now that she had thе means to reach the top herself?

"I wouldn't recommend climbing any higher."

Something in the mage's voice made her halt. She glared down at him. "Why?"

"Come down and I'll show you."

She paused, thinking. True, there must be some reason Marnok had not simply used the salve himself to climb the wall. She let go and dropped lithely to the ground. The mage was peering into crevices and under rocks, searching for something.

"This will do," he said after a minute.

She approached and squatted down to see what he had found. It was a small, unidentifiable animal, long dead. Its flesh was gone, but dried sinews bound its bones together. She could see by the worn, flat stubs of teeth in its skull that it had died an old animal. A few ragged tufts of fur still clung to the small carcass.

"If you're hungry, you might want to find something a little fresher," she noted caustically.

Ignoring her, he carried the little skeleton to the ground before the dark wall. After dabbing a small amount of the emerald salve on the dead creature's paws, he chanted a dissonant incantation in a low voice. The skeleton began to move. Ravendas raised a curious eyebrow. Perhaps the mage was more powerful than she had guessed.

"Climb," he whispered.

The animal skeleton lurched toward the wall, then began to scrabble upward, the magical salve allowing it to sink its claws into the smooth, dark stone. The skeleton was perhaps twenty feet above Ravendas when she noticed something strange. The stone some distance to the creature's right was undulating, almost as if it had turned to liquid. Suddenly she swore. As if emerging from dark water, a shape rose from the smooth surface of the wall, long and sinuous, with horns like curved scimitars and teeth like daggers. It was the head of a dragon, as perfectly black as the stone from which it sprang. Two glowing crimson slits appeared above its snout. It was opening its eyes.

"Look there," Marnok said softly, pointing to a section of wall off to the undead animal's left. Ravendas followed his gaze to see another dragon emerge from the stone. Each of the dark, serpentine heads turned toward the skeletal creature that climbed between them. Without warning, a beam of hot crimson light shot from the fiery eyes of the first dragon. The beam arced around the curved wall of the fortress. It struck the animal skeleton, but the reanimated creature kept climbing.

'The dragon's gaze didn't harm it," Ravendas uttered in amazement.

"Keep watching," the mage instructed.

Moments later the eyes of the other dragon flared. A second beam shot from its eyes, arcing around the wall from the opposite direction to strike the undead animal. As the two beams connected, their color changed from violent red to searing white. In a brilliant flash of light, the skeleton of the undead animal exploded. Smoking splinters of bone rained down on Ravendas and Marnok. The two dragon heads shut their glowing eyes and sank silently back into the smooth surface of the wall.

"Now you see why I was not so eager to begin climbing," Marnok said softly.

"How does it work?" Ravendas asked in dread fascination.

"I'm not entirely certain," the mage said, "but I have conducted a few other experiments like the one you just witnessed."

She listened then as he explained his discoveries. It seemed that within the circular wall of the fortress there resided four columns of magical energy, one situated at each point of the compass. When something-or someone -climbed the wall, a dragon's head would rise from each of the two columns that bordered the quadrant where the intruder climbed. The eyebeams of one of the dragons didn't appear to cause harm, but when the eyebeams of both dragons met, the arc of magical energy was completed, and the climber was-as they had so graphically witnessed- destroyed.

"Why don't you simply wave your staff, mage, and make wings sprout from our backs?" Ravendas said caustically. "Then we could just fly over the wall."

"And we would die just as quickly," Marnok replied evenly. "I have watched birds that flew too close to the keep. The dragons found them with their gazes easily enough."

Ravendas swore in frustration. "So why don't we smear that salve of yours over our entire bodies? Then we could just walk right through the wall."

"Yes," the mage said calmly. "And then we could just as promptly suffocate with our lungs full of rock. The salve does not make our flesh incorporeal, Ravendas. It only causes stone to flow around it."

She threw her hands up in disgust. "I suppose you have some other solution in mind that will absolutely dazzle me with its cleverness?"

A smile danced in his eyes. "No. Not yet, anyway. However, at least I have learned how the tower's defenses work. That is some help."

"Perhaps," Ravendas replied skeptically. "But then, I've found that sometimes knowledge only gets in the way. Sometimes knowing the truth can make one give up in despair." She clenched a fist. "And I am not about to give up yet"

The mage answered only with silence.

As the morning wore on, Ravendas prowled around Gur-thang, searching for something that could help them. On the west side of the fortress she discovered a tarn, a mirror to the cold blue sky. The pool lapped up against the outer wall of the fortress, and she half-wondered if there might be some secret portal beneath its surface. But instinct told her that the way into the tower was upward, over the wall. She returned to find the mage sitting on a sun-warmed stone, poring over the old book he had shown her the night before.

"I've just translated the final passage about Ckai-el-Ckaan," he said. The wind tugged at his purple cloak.

"And?"

Marnok ran a finger over the ancient parchment. " 'Know that should the Finger of Ckai-el-Ckaan ever be lifted from its resting place, Gurthang shall fall, destroying all within. There is but a single path for one who would live: he must face the sunset, and give himself to darkness.' " Slowly he shut the book. "I'm afraid that's it."

Ravendas was unimpressed. "Forgive me for saying so, but that was hardly helpful." The mage only shrugged in silence. "So what do you think it is?" she asked thoughtfully then, gazing at the dark spire of the tower. "The relic, I mean."

"A magical wand, maybe. Or a staff of great power. But if we're ever going to find out, we'll have to do something different than all those heroes who died here one by one."

Suddenly it was so clear. Ravendas took a step toward the fortress. "But that's it, Marnok. Don't you see?" By his perplexed expression, he apparently did not. " 'One by one they came, and one by one they perished.' You read it yourself in that damned book of yours. In the past, the arrogant bastards who tried to climb Gurthang did it alone." She fixed him with her indigo gaze. "But there are two of us."