Tasha watched tensely over the shoulder of the transporter chief as she slid the energize bars. Rather than looking at the materializing form of the old man in his teal uniform, she kept her eyes firmly on the transporter display. The subroutine that Data had added briefly displayed a cross-section of the man's skull at the brain stem - refreshingly, one without an alien parasite attached. She glanced over at Geordi, who likewise confirmed with a nod that the doctor was clear.
"Doctor Quaice," Yar began. "I'm Lieutenant Commander Yar; this is Lieutenant La Forge. Thank you so much for offering your help."
"Of course, young lady," the old doctor beamed kindly. "Happly to do what I can for Beverly's ship. I take it she's monitoring whatever this mysterious ailment is from Sickbay? Always did work too hard, that one. Told Jack the same thing."
"Not quite, sir," Geordi replied. "Actually, Doctor Crusher is one of the patients. If you'll follow us, please?"
The man frowned as he walked alongside the crew members. "Oh, well, if she's been taken down, that explains why I'm needed. She's easily one of the best medical minds in Starfleet, you know. I've told Doctor Tobin on several occasions that she needs a job at Headquarters… probably his, to be honest."
"Doctor," Yar broke in, "this is a delicate situation. Beverly Crusher, along with our captain and ship's counsellor, have been infected by intelligent parasites that are controlling their bodies."
They walked in silence for nearly a minute before Quaice responded with a simple. "Ah."
The old man seemed to steel himself as he walked into sickbay. Data and a single nurse stood on opposite sides of the surgical arch below which Doctor Crusher lay, struggling mightily against the forcefield-enhanced clamps restraining her arms and legs. Worf stood nearby, clearly on guard.
"Doctor!" Beverly cried out upon seeing the uniform-clad man. "Please, help! I don't know why they're doing this to me! They think I'm not myself!"
"Why is she conscious?" Yar asked in concern.
"Stunning phaser beams had no effect," Data volunteered. "We did not wish to risk a higher setting."
"Oh dear," Quaice said as he approached the operating table. "Beverly, do you know what's going on here?"
"No, doctor! They abducted me; I have no say in this! Whatever they want you to do, I do not consent!"
"You don't remember me, do you?" asked the older doctor. "You can't even tell me my name."
"I'm sorry, sir, I… have been very forgetful lately. Please." The tears ran freely down her cheeks. "Just let me go. I haven't hurt anyone."
"That remains to be seen." With deft fingers, the man activated the medical arch, pulling out a scanner with his off hand and, using the latter together with the former, adjusted the position of the diagnostic and surgical device to immediately above her shoulders and neck. "I'm an old friend of Beverly's and her late husband's by the way - and a close mentor. Whatever you are, you should have done your homework better." The display near the head of the table showed a disembodied map of a human brain and spinal cord, the parasite nestled underneath the system extending thick tendrils that wrapped around the nervous tissue until they appeared indistinguishable.
"We mean you no harm," Crusher switched seamlessly to a new plea. "We have taken care of our hosts, kept them free from any injury. Please don't kill us."
"If you don't intend us harm," Tasha asked, "then why were we diverted back to Earth? Why try to deceive us, rather than communicating with us?"
The bound woman swallowed, but gave no immediate answer.
"Remarkable," Doctor Quaice exclaimed, looking at the readouts and triggering more detailed scans. "The creature's not just controlling her forebrain. It's stimulating her autonomic systems as well. Hormone production, parasympathetic systems. It's manipulating adrenaline and lactic acid levels to maximize muscle and performance and proprioception."
"Yes!" Beverly shouted. "We make our hosts better, you can see that! Even smarter, over time."
Tasha pounced on that. "What do you mean, over time?"
"It takes weeks for us to fully integrate with our hosts. But by then, our two brains are like one! A shared consciousness with all the memories and skills of both. Like a joined Trill!"
"A what?" Tasha was confused. "What do the Trill have to do with any of this?"
The older doctor flinched a bit at this. "Ah! Er… hm." Quaice finally said, "I am going to have to ask you all to disregard that comment about the Trill, please. They have some cultural traditions that they've asked to remain secret from the rest of the Federation for the time being. Need-to-know only."
Tasha shook her head, re-focusing on the issue at hand. "Can you remove the parasite, doctor?"
"Symbiont," Crusher insisted. "And I have a name. Grionta."
"Grionta," Data repeated. "Would you be willing leave Doctor crusher's body voluntarily as a demonstration of your peaceful intentions?"
"For a short time, yes," Crusher agreed. "But without a source of nutrition, I'll die in just a few hours."
Tasha promised, "You have my word that if Doctor Quaice can't find a safe substitute for you," she swallowed in growing disgust, "you can use my body to feed. We are not in the habit of killing peaceful sapient lifeforms, however they sustain themselves."
Doctor Crusher's gaze met Yar's for several seconds, seeking out some sign of her sincerity. With a nod, the woman opened her mouth… and a large purple beetle-like creature crawled out of it.
Yar nodded to Quaice at the same time that she noticed, out of the corner of her vision, that Worf had subtly drawn his phaser although he held it pointing down at his side. The old man deftly and delicately scooped up the alien, holding it along its carapace to avoid its prominent pincers. "Remarkable," he exclaimed again, before placing it down on a nearby specimen tray.
"How is Doctor Crusher?" Geordi asked.
Quaice turned back to the surgical arch and display. "Hm. Catatonic, as though she had suffered a major neural trauma. The actual damage is very minor; I'm setting the arch to repair it automatically." He nodded. "She should awaken any minute with only a minor headache."
"Could you have removed the alien without its cooperation?" Yar asked.
"Not without risking serious brain damage," Quaice frowned. "With Beverly back, though…" he smiled. "Like I said, the girl's a genius. I'd bet she'll come up with something."
"In the meantime," Data suggested, "perhaps we can negotiate a peaceful resolution with the other symbionts as well."
"Parasites, Data," La Forge corrected.
The android cocked his head in confusion. "Is it not preferred, when involved in diplomatic relations -"
"Yes, right, of course," Geordi acknowledged. "But look at it. It's a mind-controlling bug, Data. It certainly didn't care anything about Doctor Crusher's feelings."
With a nod, Data followed Yar out of sickbay.
*****
Had Tasha not already known that the woman in front of her was not Soriana, the laugh would have done it.
The real Soriana giggled or snickered; an understated reaction that spoke of kind-hearted mischief. But the woman on the other side of the forcefield gave a full-throated horse laugh teeming with derision. It was mocking and cold - wholly dismissive of Yar's proposal.
"What sort of a queen-damned fool do you take me for," she snarled, "to voluntarily give up my only leverage? I literally have your crewman's brain in my hands, and you expect me to just release her to show my goodwill? On your word? Please, Tasha." She smiled, and that at least looked no different than the Haliian. "You can do better than that."
"Grionta and Bristak agreed," Yar pointed out.
"Fools," she sneered. "Which is why I'm the mission commander, not them. Fortunately, it doesn't matter. One Starfleet officer is as good as three as far as leverage is concerned."
"They have a commitment from me that we'll feed them. From my own body, if necessary."
"How heartbreakingly noble of you, Lieutenant Commander. But if you want Soriana Turhal back intact, I'm going to need a little more."
Tasha looked to Data briefly, but his face was as expressionless as usual. "We'll extract you by force, if necessary," she pointed out.
"I'll destroy Soriana's higher brain functions, if necessary," she countered. "I don't need them to survive. My tendrils can whip through her cortex with enough force to eliminate any chance of full recovery. Personality, memories, language - hope you have the time to bathe and feed her."
Tasha's fists clenched; it matched what Quaice and Crusher were saying. She wished the captain were able to handle this, but his brain had suffered more trauma than Crusher's. They wouldn't try to wake him for at least another eight hours. "What are your demands?" she relented.
"You let us go," she explained. "I will direct you to a world with several of us already hiding on it. You beam me, in this body, down with my team. I'll hand us off, and you'll beam the body back without me."
Data asked, "What assurance do we have that you will leave Lieutenants Commander Turhal's body once we have facilitated your escape?"
She shrugged. "You'll keep a pattern lock on her until I signal you. I can't run away faster than you can get me back."
With a nod, Yar announced, "We'll consider it." She stood and walked out of the brig, nodding to the guard to shut the door.
It rankled, but what choice did she really have?
*****
Tasha entered the transporter room where Soriana Turhal stood impatiently on the pad. The first officer handed the mind-controlled Hallian the equipment case. "Doctor Crusher insists the nutrient broth will sustain each of the three of you for forty-eight hours at least. There's a third container in there for you."
The other woman nodded. "I shouldn't need it, as long as you haven't tried to set up some sort of trap for us."
"No need," Yar said. "We've updated our transporter bio-filters to detect you, and forwarded the info to Starfleet Headquarters and Medical. You won't catch us by surprise again."
That grating laugh sounded. "Trust me, Tasha - this won't be the last time we talk. You have no idea who you're dealing with."
Without breaking her stare, Yar hit her comm badge. "Bridge, the entity is ready to transport."
"Acknowledged," the voice of the captain sounded. "Remind our guest that I expect my counsellor's brain back in one piece."
"Energize," Yar ordered. She waited until the beam had fully evaporated before returning to the bridge.
*****
Beverly waited tensely beside the prepped operating table, her old friend and mentor beside her.
"Like old times, eh?" Quaice quipped. She could tell he was as on edge as she, but he'd always tried to defuse it with humor.
"Not my favorite memories, no offense," she answered back.
"Anything unusual about operating on a Haliian?"
Crusher shook her head. "Standard humanoid physiology. Nerve clusters protrude from the anterior cranium to enhance their telepathic reception, which are a common point of injury in the event of head trauma. They have a second stomach and large cecum to better digest plant fibers. No gallbladder. Liver and kidney functions are both carried out by a single pair of-"
"How do you remember all that?" the man shook his head. "There are hundreds of species in the Federation."
"But only three dozen on my ship. Every crew member is my responsibility; they count on me to treat them with as much skill as though I were a doctor from their own world."
Quaice nodded in understanding and respect. "What was it like-"
Before he could finish the question, Soriana materialized on the table. The blood dripping from her nostrils forecasted significant injury. The two doctors had no time to chat.
*****
"Since the fleetwide alert, over three hundred personnel appear to have deserted their posts, including six admirals." Norah Satie looked sternly out from the ready room desk screen.
"How many ships have disappeared?" Picard inquired.
"Only seven, thank goodness. A surprisingly large number - including your friend Keel's ship, the Horatio - managed a Code Seven and got their bugs in the brig. A testament to good training, I'd say."
"You're not worried about how easy it is to get a mutiny going?" he asked, only half-serious.
"Quite the opposite. Starfleet is about loyalty to the Federation, not your captain," Rear Admiral Satie gave a thin smile. "I'm happy to see that a captain who loses the confidence of his crew can be so thoroughly tossed on his ear."
"I can see the appeal, although it's a little hotter in my seat," Picard agreed. "Did we ever figure out where they were from, or what they want?"
"Investigations are ongoing; we have a few here at Headquarters to… interview." Her voice took on a more acerbic tone. "They were carefully consolidating power in Starfleet Command for months, and we think they were nearly ready for a major push. Towards what, no one is sure."
"Well, whatever it was, they'll find it far more difficult to gain any sort of foothold in Starfleet again," Picard insisted.
"Maybe," Satie relented, "but it also exposed some real weaknesses in our vetting procedures and command structure. I'm going to be pushing for Command to have much stronger powers of internal investigation going forward. And more scrutiny of ship reports, as well."
Picard nodded. "Let me know how I can help, Admiral. If this incident has taught us anything, it's the need to be vigilant… and that no one is above suspicion."