They were on the floor now, and Chris saw the two tunnels he had noted in the chamber of Crius, one leading west and the other east. All they had to do now was traverse the sixty or seventy meters to the eastern tunnel. Chris nervously fingered the unusual weapon he had removed from Valiha's saddlebag. It felt reassuringly cold and hard and unyielding as he ran his thumb over the two sharp points. Perhaps he would not have to use it.
"I confess I didn't see until just now why you brought that creature along," Tethys said. "It should have been obvious. Am I right?"
Chris said nothing. They were ten meters from the tunnel entrance and still moving.
"I'm getting impatient," Tethys said. "You may be the Wizard, but there are limits. I'm talking about the Titanide. How thoughtful of you to bring dinner. Come here, Valiha."
Valiha stopped and her head turned slowly. She looked at Tethys for the first time. Chris did not wait to see what she would do. He took a firm grip on the large fork which had been part of Valiha's carving set, dropped back a step, and thrust it solidly into the fleshy part of Valiha's rump. For one awful moment there was no reaction; then Valiha moved so fast she seemed to blur. He caught a glimpse of her tail as it vanished into the tunnel, heard her shriek and the clatter of her hooves; then all other sounds were drowned by a piercing whistle. They were into the tunnel, followed by a blast of heat and a rising wind. They were surrounded by choking fumes. Tethys was filling her lake as quickly as she could. The floor they were running on seemed level; when the acid brimmed over the edge of the moat, it would follow them.
As they ran, they were joined by fluttering, batlike creatures. Chris knew by their orange glow that they were the same animals which had lighted their long descent and which he hoped would also populate the tunnels. Whatever they were, they did not like acid fumes any more than he did.
One part of his mind noted that he had found one more thing he could do better than Robin. He was a faster runner. She had fallen behind, and he slackened his pace to allow her to catch up. They both were coughing, and his eyes were watering, but the fumes were not as thick as they had been.
He heard her gasp and fall. It was not until he had stopped himself and turned back that he heard the sound of a trickling liquid he suspected was not water. For one wild moment he was ready to run away, but instead, he hurried back to her, toward the sound of the approaching wave of acid. It was almost completely dark now since the luminescent creatures, less altruistic than he, had not halted in their flight.
He collided with her. Why had he assumed she would need help getting up?
"Run, idiot!" she yelled, and he did run, behind her this time, the only light coming from the distant fliers, the pale glow of which made a halo around the animated shadow she had become.
"How long do you think we need to keep running?" she called back to him.
"Until I can't hear the acid splashing behind me."
"Good plan. Do you think we can outrun it? Is it getting closer?"
"I can't tell. I can't hear it unless I stop."
"Then we might keep running until we drop," she pointed out.
"Good plan," he said.
It didn't seem likely that the glowbirds were flying faster. Yet they were farther ahead than they had been, so he and Robin must be slowing down. His own breath was coming in ragged gasps, and his side was hurting badly. But he had detected no rising of the floor. For all he knew, their present location might actually be lower than the floor in the grotto of Tethys. It was possible that Tethys could flood the entire length of what Chris devoutly hoped was a 300-kilometer tunnel linking Tethys with her sister, Thea. But of course, it was possible the tunnel did not lead to Thea at all. It might end at any moment. It might begin to slope down, and they would find they had been seeking their salvation in what was actually a drain for excess acid. But there was nothing to do but run. If there were an end to the tunnel, Valiha would find it first, and they had not yet caught up with her.
"I think ... it's gone ... up. Don't ... you?"
"Maybe. But how ... far?" Privately Chris did not think they had gained any ground at all, but if thinking they were rising made it easier for Robin to put one foot in front of the other, that was fine with him.
"I can't... do this much ... longer."
Neither can I, he thought. The darkness was nearly complete now. The floor was not as level as it had been, so the danger of falling was increased. Getting up again would be quite a project.
"A little longer," he wheezed.
They bumped into each other, moved away, and hit again. When Chris moved to his right, he hit his shoulder against the invisible tunnel wall. He had his hands out in front of him, no longer able to tell if the glow he was following-seemingly many kilometers ahead-was real or just an afterimage on his retinas. He was afraid the tunnel would make a turn and he would crash into the wall. Then he realized he was moving so slowly by now that he could not be badly hurt in a collision.
"Stop now," he said, and fell to his knees. Robin was somewhere in front of him, gasping and coughing.
For an undetermined time it did not really matter that acid might be creeping along the tunnel behind him. He pressed his cheek to the cool stone floor and let himself go limp. Only his lungs continued to labor, at a steadily decreasing tempo. His throat was burning, and his saliva was thin but so plentiful he had to keep spitting out sticky ropes of it. At last he raised his head, put his palms to the floor, got to his knees, and, by force of will, held his breath for a few seconds, listening. It was no good. His ears thrummed with blood, and Robin, close enough to touch, still gasped and panted loudly. He thought he might hear the approach of the acid if it came in a roaring wave, but it would not. If it were still coming, it would be rising silently. He reached over and touched Robin's shoulder.
"Come on. We'd better get moving again."
She moaned but got up with him. She fumbled for his hand, and they began to walk. His shoulder rubbed the right wall; they continued that way, Chris touching cool solidity with one hand, warm flesh with the other.
"We have to be going up," Robin said finally. "If it was down, the stuff would have washed over us a long time ago."
"I think so, too," Chris said. "But I don't want to bet my life on it. We have to keep going until we can get some light."
They walked on, Chris counting the steps, not really knowing why he was doing it. He supposed it was easier than thinking about what might lie ahead.
After several hundred paces Robin laughed.
"What's funny?"
"I don't know, I ... I guess it just occurred to me... we made it!" She squeezed his hand.
Chris was astonished by her reaction. He was about to point out that they were far from safe, that the road ahead was certainly filled with dangers they could not even guess, when he was suddenly filled with an emotion as powerful as any he had ever experienced. He realized he was grinning.
"Damn. We did, didn't we?" Now they both were laughing. They embraced, slapping each other on the back, shouting incoherent congratulations. He squeezed her hard, unable to stop himself, but she made no objection. And just as suddenly he found himself crying with a smile still on his face. Neither of them could control the swift passage of emotions brought about by the release of unbearable tension. Nothing they said made sense. And in time they were spent, still clinging to each other, still standing, rocking gently and wiping away stray tears.
When Chris finally chuckled again, Robin nudged him, "What's funny now?"