Vaughn straightened and turned toward the main viewscreen, as though he would be able to see the unexpected planet across the cold kilometers. He looked at the rock fragments tumbling silently through space, barely visible in the darkness as they caught the negligible light of the distant sun, and he thought he suddenly understood something. “Ensign,” he told ch’Thane, “transfer the coordinates of the planet to the conn.” Vaughn paced back over to the command chair. “Shields,” he said.

“Shields up,” Bowers confirmed a moment later.

“Ensign Tenmei,” Vaughn said, “take us in over the ecliptic.” The debris of the system had spread out more or less along the plane of the solar equator. “Best speed.”

“Aye, sir,” Prynn said. Her hands moved deftly across the flight-control console, summoning Defiant’s wings. The bass hum of the engines sent deep vibrations through the ship’s structure.

Vaughn sat down and gazed toward the viewscreen again. The stars shifted and the wreckage of the system fell away as Defiantchanged its heading. Vaughn imagined the energy pulse repeating across decades, across centuries, growing ever stronger, battering planets and moons into nothing but shards, and he wondered how a lone world could have survived when nothing else had. And as Defiantbrought the crew closer to the mystery, he could only conjure up one explanation: the planet had to be the source of the pulse.

The atmosphere roiled, a cauldron of churning shadows. Currents and eddies seethed through the dark, gray sea of clouds, imparting to it an inhospitable, even violent, appearance. The cover ensphered the planet, an inexplicable mixture of aeriform elements and energy surges—energy reminiscent of the pulse itself, though on a much smaller scale.

Vaughn sat in the command chair and watched the turbulent scene on the viewscreen. Ensign ch’Thane had calculated the orbits of the Vahni world and the one below, as well as the sidereal motions of their respective stars, and verified that the pulse had come from here. Further, the science officer had utilized stable cloud masses at the poles to determine the rotational period of the planet, allowing him to pinpoint the area on the surface where the pulse had originated. Defiantcircled above that location now in a geosynchronous orbit.

“Anything?” Vaughn asked, his eyes still on the viewer, still on the heaving, twisting mass of clouds obscuring the planet. The sight put him in mind of another world, from across the galaxy and long ago, beset by the throes of a nuclear winter. In this case, he thought, the comparison might turn out to be apt.

“Negative,” ch’Thane responded, checking his readouts. “I’m still not receiving any telemetry from the probe.”

“It should emerge from the atmosphere in just under four minutes,” Lieutenant Bowers offered.

“Thank, you,” Vaughn said. When sensors, communications, and transporters had failed to penetrate the sea of clouds, Vaughn had ordered a probe launched, in the hope that it could reach the surface and gather useful data about whatever was down there. Contact with the probe had been lost as soon as it had descended into the atmospheric cover, but it had been programmed to return to the ship at a specified time.

The bridge grew quiet as the crew waited, only the gentle rumble of the thrusters intruding into the stillness. Vaughn glanced around and saw Nog and Prynn staring at the viewscreen, while Bowers and ch’Thane studied their panels. The crew seemed bound by a sense of tension, Vaughn thought, which he recognized as an amalgam of anticipation and anxiety; they wanted very much to help the Vahni, and at the same time, had doubts about whether they would be able to do so. Whatever data the probe provided would likely determine the nature and extent of the action they could take.

Vaughn recalled the terrible threat to Europa Nova not long ago, and he understood that if the Defiantcrew could not put an end to the pulses, then the Vahni would have to be evacuated from their world, just as the Europani had. Considering that first contact had only just been made, and that the Vahni did not possess warp drive, suggesting a rescue effort to Starfleet would be a delicate matter. The notion of sending a squadron of evacuation vessels into the Gamma Quadrant, and the massive logistics involved in transporting more than a thousand times as many individuals as had been moved from Europa Nova, would also not be welcomed easily. Vaughn felt certain, though, that he could convince the right admirals—and the right Federation councillors—to see the Vahni civilization saved. But unlike the Europani, the Vahni would never be able to return to their home, which would doubtless be destroyed by the next pulse.

“One minute,” Bowers announced into the silence. And then, “Thirty seconds,” and after that, “Ten.” Vaughn watched the viewscreen, though he knew the ship’s sensors would pick up the probe well before his eyes did. “Zero,” Bowers said at last.

Vaughn waited. Ten seconds. Twenty. Half a minute. The low buzzes of failure—indications of unsuccessful attempts to communicate with the probe, and to scan for it—reached Vaughn from the tactical and sciences stations. “Ensign ch’Thane?”

“There’s no contact from the probe,” he answered, a hint of disappointment rising in the science officer’s usually even voice.

“I can’t read it on sensors either,” Bowers added.

“All right,” Vaughn said, running a hand through the silver hair of his beard. “Let’s give it a little longer.” He reached over to the console to the left of the command chair. He tapped at the controls, walking his way through a couple of menus until he accessed a chronometer. He noted the ship’s time, and then allowed fifteen minutes to pass. The bridge crew said nothing, alternately checking their instruments and gazing up at the viewscreen at the convulsing atmosphere displayed there. “Report,” Vaughn finally said.

“Still no contact with the probe,” ch’Thane responded at once. Bowers simply looked up from his console and shook his head when Vaughn looked his way.

“All right,” Vaughn said. “Either the probe failed on its own, or something caused it to fail. Opinions?”

“The energy surges within the atmosphere might have affected it,” Nog suggested. “They could have shorted out or overloaded some of its systems. If guidance or propulsion were damaged, then the probe might have crashed.”

“Sir,” Prynn said, turning her chair around to face Vaughn, “even if the probe withstood the energy surges, it may not have survived its flight through the clouds.” She peered over her shoulder toward the viewscreen, at the writhing atmosphere, then looked back at him. “It looks like a rough ride.”

Vaughn nodded and stood up from the command chair. “Is it possible,” he asked the bridge crew, “that the clouds themselves are the source of the pulse?”

“I don’t think so, sir,” ch’Thane said. “There doesn’t appear to be any means within the atmosphere to generate that amount of energy. I think it more likely that the clouds have retained the energy within them as a result of the pulse passing through them from below.”

“I concur, sir,” Nog said. “The elemental composition of the clouds wouldn’t support the production of energy.” Bowers also added his concurrence.

“So we clearly need to find out what’s down there,” Vaughn said. Prynn turned back to her console as he walked toward the sciences station. He stopped to the left of the conn. “Ensign ch’Thane,” he said, “is it possible that some sections of the atmosphere are less dense than others? Or contain fewer or weaker surges?”

The science officer looked up from his panel. The soft lights of his display lent a slight, orange cast to one side of his blue face and white hair. “Yes, sir,” he said. “It may even be likely; the atmosphere is clearly in flux, which would probably leave some areas not as deep as others. But I’m not sure if the sensors will be able to penetrate the clouds at any depth.”