“It was Tuvok’s idea to stage a quarrel to distract Jarquin until we could locate you. The vase was the first thing that came to hand.”

“Fortunate for all of us that it did,” Selar suggested.

“Tuvok, how do you do it?” Sisko asked him during aquiet moment. The ship was on autopilot, and he was allowing himself some downtime to whip up a soufflé with the last of the vegetables from Tenjin.

The Vulcan was adding nutrients to the potting soil containing the orchid one drop at a time. “Do what?”

“Spend months or even years away from your family? Maybe it’s just thinking of all those dead on Quirinus, but all I want to do is rush home and be with my wife and son.”

Tuvok found the nutrient level to his satisfaction, set the orchid under its gro-light, and gave Sisko his complete attention.

“I submit, Mr. Sisko, that all you have wanted to do since we left Earth is return to your wife and son. However—” he said before Sisko could object. “To answer your question, it was necessary for me to leave Starfleet in order to start a family. Once I was confident my sons and my daughter were sufficiently mature not to require my guidance on a daily basis, I was free to return. As I understand it, you and your spouse have been fortunate enough to be assigned to the same ships for much of your career.”

“It’s true, I’ve been a little spoiled. This is the first time I’ve been away from Jennifer this long since Jake was born. Maybe if he were a little older I wouldn’t feel so bad, but…”

Uncertain what answer Sisko was looking for, Tuvok said, “It has been my experience that one of the most difficult, yet most essential, aspects of being a parent is knowing when to let go.”

For some reason Sisko found himself thinking of when Jake was a toddler and first learning to walk, how he’d gone from room to room making sure everything was safe. He’d put extra carpeting in the living area, cushioned the corners of every low table, and still followed the boy around with his hands outstretched, ready to grab him any time he seemed about to fall. It had been his own father who set him straight.

“You intend to be around to cushion his fall for the rest of his life?” Joseph Sisko had demanded. Ben had some leave time and had dropped in to New Orleans so that Jake could spend some time with his grandfather and vice versa. They were in the restaurant just before opening, setting the tables.

“I just don’t want him getting hurt,” Ben had answered, not taking his eyes off Jake, who was toddling from table to table, and from chair to chair around each table, rocking the chairs against the hardwood floor to hear their sound and laughing at his newfound skill as he went.

“And what’s that supposed to teach him?” Joseph wondered, smoothing out each tablecloth as they went.

Ben didn’t answer. Jake had gotten hold of the edge of one tablecloth and was starting to pull. “Be careful, Jake-O. Don’t do that; you’re going to fall—”

Just then he felt his father’s grip on his arm, hard.

“Let the boy go, Ben. How else is he going to learn?”

“But it’s a hardwood floor,” Ben started to say. “There’s no protection. If he—”

But Joseph refused to relieve his grip, and Jake kept pulling on the tablecloth until it slipped off the table, knocking him back on his well-diapered bottom. Jake seemed surprised for a moment, then giggled, pulled the tablecloth over his head, and crowed. “Peekaboo!”

“Peekaboo to you, too, young man,” Joseph said, letting go of Ben’s arm and retrieving the tablecloth. “Give that to Grandpa, now, and go on about your business.”

The boy clutched the rungs of the closest chair, pulled himself upright, and continued his exploration around the next table and the next. His father, whose every muscle had tightened when the boy fell, finally relaxed.

“He just got his first lesson in physics, Ben,” Joseph said. “And you a good lesson in parenting. Sometimes you’ve got to let them go.”

Now Tuvok was telling Sisko the same thing. Would he ever be able to let Jake go? He guessed he’d have to learn the answer to that question one day at a time.

“The organism on Quirinus is indeed the same,” Selar reported during the next medical briefing with Uhura and Crusher. “At least as evidenced in blood and skin samples taken from those quarantined inside the enclosure.”

“But—?” Uhura prompted her, hearing something in her tone.

“But serum and skin samples taken from the outworlder killed by the villagers show no trace of the organism.”

“What if he had nothing to do with the infection?” Uhura asked.

“That is possible,” Selar acknowledged. “However, what is unusual is that his blood was remarkably free of any active organisms or even background noise.”

“ ‘Background noise’?” Uhura asked.

“Everyone’s blood is a road map of their medical history,” Crusher supplied. “Immunizations, childhood illnesses, even the common cold, leave antibodies in the bloodstream long after they’re introduced into our systems. That’s why immunizations work. If you get a measles shot, for instance, you won’t catch measles, because the old germs are telling the new germs on the block: ‘Been there, done that, go somewhere else.’ ”

“Gotcha,” Uhura said. “But you said ‘remarkably’ free.”

“Indeed. Given the small volume of blood Tuvok was able to obtain, I cannot say with certainty that the stranger was entirely free of antibodies, but there were none in the sample.”

“None?” Crusher echoed her. “That’s impossible.”

“Maybe he was just very healthy,” Uhura suggested.

“Hypothetically,” Selar said, “someone who had never received any immunizations, who had never been ill nor exposed to anyone who was ill, or someone whose entire blood supply had been dialyzed and replaced, might show such a pattern.”

“But—?”

“But there’s no such animal,” Crusher said.

“Such an individual would not have been cleared for offworld travel without receiving new immunizations,” Selar clarified. “And since Tuvok’s scans indicate this individual was most likely a Romulan surgically altered to more closely resemble a Quirinian—”

“Something stinks,” Uhura finished for her.

Selar, less literal minded than most Vulcans, merely said, “Agreed.”

“Is it possible,” Uhura said, thinking it through as she asked it, “that a person’s biology could be programmed to make them immune to a disease that they could spread to others?”

“Not by our science,” Crusher said. “It sometimes occurs naturally. Carriers who are immune, like Typhoid Mary.”

“Not by our science,” Selar agreed. “But perhaps the Romulans—?”

“That could solve the mystery of the delivery system,” Crusher suggested. “Admiral, are you okay?”

They sometimes forgot that, tough as she was, Uhura was no longer a young woman. This thing had been keeping her up nights, and it showed.

“Okay as I’ll ever be,” she said, passing a hand over her eyes and straightening the momentary sag in her shoulders. “Carry on.”

Their next stop was a world called Sliwon.

Vulcan, like many worlds, eventually entered a period of aggressive colonization, and perhaps a ship or ships from that era had ventured as far as Sliwon. Or perhaps its people were descendants of some members of the Sundering’s hegira who refused to travel further. Perhaps, too, there was an indigenous population of humanoids on Sliwon when they arrived, or perhaps the legends of the Preservers populating the galaxy with humanoids could once more be given evidence here. In the event, the Sliwoni, like the Rigelians, were a bit of both.

And perhaps it was the overlarge moon that made its people moody and given to extremes of temperament, or perhaps it was the uneasy agglomeration of their biology that made them quick of temper and prone to quarrel. It was Surak himself who, according to some accounts, said “Put two Vulcans in a room and you end up with three arguments.” Blessed with a mild climate, abundant rain and rich soil, in between arguments the Sliwoni grew things. They clung to certain customs, such as the use of archery for personal weaponry, even as they advanced in-system space travel. They had no desire to venture beyond their own system, though they welcomed visitors from offworld, particularly those who had things to trade, but insisted that they land their ships instead of leaving them in orbit.