The older man had a friendly, matter-of-fact air to him and a self-confident walk. The faded captain’s insignia on his shoulder indicated that he was the senior of the two in rank as well as age. “Darya Lang?” he said as soon as they were within easy speaking distance. He smiled and held out his hand, but not to shake hers. “I’ll take your entry forms. I’m Captain Rebka.”

Add “brusque” to the list of words describing the inhabitants of the Phemus Circle, she thought. And add “unkempt” and “battered” to Rebka’s physical description. The man’s face had a dozen scars on it, the most noticeable running in a double line from his left temple to the point of his jaw. And yet the overall effect was not unpleasant — rather the opposite. To her surprise, Darya sensed the indefinable tingle of mutual attraction.

She handed over her papers and made internal excuses for the scars and the grimy uniform. Dirt was only superficial, and maybe Rebka had been through some exceptional misfortune.

Except that the younger man looked just as dirty, and he had his own scars. At some time his neck and one side of his face had been badly burned, with a bungled attempt at reconstructive surgery that would never have been accepted back on Sentinel Gate.

Maybe the burn scars had also left the skin of his face lacking in flexibility. Certainly he had a very different expression from Rebka. Where the captain was breezy in manner and likeable despite his grubbiness and lack of finesse, the other man seemed withdrawn and distant. His face was stiff and expressionless, and he hardly seemed aware of Darya, although she was standing less than two meters from him. And whereas Rebka was clearly in top physical shape, the other had a run-down and unhealthy look, the air of a man who did not eat regular meals or care at all about his own health.

His eyes were at variance with his young face. Dead and disinterested, they were the pale orbs of a man who had withdrawn from the whole universe. He was unlikely to cause Darya any trouble.

Just as she reached that comforting conclusion the face before came alive and the man snapped out, “My name is Perry. Commander Maxwell Perry. Why do you want to visit Quake?”

The question destroyed her composure completely. Coming without the preliminary and traditional courtesies of Alliance introductions, it convinced Darya Lang that these people knew — knew about the anomaly, knew about her role in discovering it, and knew what she was there to seek. She felt her face turning red.

“The — the Umbilical.” She had to struggle to find words. “I — I have made a special study of Builder artifacts; it has been my life’s work.” She paused and cleared her throat. “I have read all that I could find about the Umbilical. But I want to see it for myself and learn how the tethers work on Opal and Quake. And discover how Midway Station controls the Umbilical for the move to space at Summertide.” She ran out of breath.

Perry remained expressionless, but Captain Rebka had a little smile on his face. She was sure that he saw right through her every word.

“Professor Lang.” He was reading from her entry papers. “We do not discourage visitors. Dobelle needs all the revenue it can get. But this is a dangerous time of year on Opal and Quake.”

“I know. I have read about the sea tides on Opal, and the land tides on Quake.” She cleared her throat again. “It is not my nature to seek danger.” That at least was true, she thought wryly. “I propose to be very careful and take all precautions.”

“So you have read about Summertide.” Perry turned to Rebka, and Darya Lang detected a tension between the two men. “As have you, Captain Rebka. But reading and experiencing something are not the same. And neither of you seems to realize that Summertide this time will be different from all others in our experience.”

“Every time must be different,” Rebka said calmly. He was smiling, but Darya Lang could feel the conflict. Rebka was the older and the more senior, but on the issue of Summertide Commander Perry did not accept the other’s authority.

“This is exceptional,” Perry replied. “We will be taking extraordinary precautions, even on Opal. And as for what may happen on Quake, I cannot begin to guess.”

“Even though you have experienced half a dozen Summertides?”

Rebka had lost his smile. The two men faced each other in silence, while Darya looked on. She sensed that the fate of her own mission hung on the argument that they were having.

“The Grand Conjunction,” Perry said after a few seconds. And finally Darya had a statement that made sense to her as a scientist.

She had studied the orbital geometry of the Mandel system in detail while working on the Lang catalog of artifacts. She knew that Amaranth, the dwarf companion of Mandel, normally moved so far from the primary that the illumination it provided to Dobelle was little more than starlight. However, once every few thousand years its motion brought it much closer, to less than a billion kilometers of Mandel. Gargantua, the remaining gas-giant planet of the system, moved in the same orbital plane, and it, too, had its own point of close approach to Mandel.

Dobelle’s critical time of Summertide usually occurred when Gargantua and Amaranth were both far from Mandel. But all three orbits were in resonance lock. On rare occasions, Amaranth and Gargantua swung in together to Mandel, at a time that coincided with Summertide for Opal and Quake. And then…

“The Grand Conjunction,” Perry repeated. “When everything lines up at periastron, and the sea tides and land tides on Opal and Quake are as big as they can possibly be. We have no idea how big. The Grand Conjunction happens only once every three hundred and fifty thousand years. The last time was long before humans settled Dobelle. But the next time will happen just thirty-three days from now — less than two standard weeks. No one knows what Summertide will do to Opal and Quake then, but I do know that the tidal forces will be devastating.”

Darya looked at the soft ground beneath their feet. She had the terrible feeling that the flimsy mud-raft of living and dead plants was already crumbling under the assault of monstrous tides. No matter what the dangers might be on Quake, surely they were preferable to staying on Opal.

“So wouldn’t you all be safer on Quake?” she asked.

Perry shook his head. “The permanent population of Opal is more than a million people. That may seem like nothing for someone like you, from an Alliance world. But it is a lot for a Circle world. My birth planet had less than a quarter of that.”

“And mine less than an eighth of it,” Rebka said mildly. No one stayed on Teufel who had any way to get off it.

“But do you know the permanent population of Quake?” Perry glared at both of them while Lang wondered how she had ever thought him calm and passionless.

“It is zero,” he said after a pause. “Zero! What does that tell you about life on Quake?”

“But there is life on Quake.” She had studied the planetary index. “Permanent life.”

“There is. But it is not human life, and it could not be. It is native life. No human could survive Quake during Summertide — even a normal Summertide.”

Perry was becoming increasingly assertive. Darya knew that her case for visiting Quake was lost. He would deny her access, and she would get no closer to Quake than the Starside spaceport. As she decided that, help came from an unexpected direction.

Rebka turned to Max Perry and pointed a thin finger up to Opal’s cloudy skies. “You are probably right, Commander Perry,” he said quietly. “But suppose strangers are coming to Dobelle because it will be the Grand Conjunction? We did not consider that possibility when we were examining their applications.” He turned to stare at Darya Lang. “Is that your real reason for being here?”