The soft chirrup from the monitor sounded in the quiet of Sickbay.

Katherine had been sifting through the remoter reaches of the toxicology databases in hope that she might turn up something that might be useful in combating the chemicals in the stranger's brain, though she was all too well aware that it was probably wasted effort. It was not a cocktail she had ever personally encountered, though she was aware of the properties of the individual substances from various avenues of past reading and study, but now she was concentrating on analysing its combined workings in detail her preliminary findings were not encouraging.

Abandoning her computer screen, she rose and walked quietly to the occupied bio-bed.

The man on it was waking. His head moved, and he whimpered softly.

She touched his shoulder gently, hoping to reassure him. "Hush. You're quite safe."

His eyes snapped open. The irises were the colour of storm clouds.

And he snarled.

=/\=

"Fear." Deanna Troi glanced across the room at the bed's occupant. "Captain, he's terrified. He doesn't understand who we are or where he is."

Jean-Luc tried not to follow her gaze automatically. It had quickly become apparent that the old man hated being looked at, and the more people who did so the more agitated he became. Only when he felt himself to be unobserved did he relax even a little, and even then his chest vibrated to a succession of low, warning growls.

"At least I could do one thing for him," Katherine commented. "He was losing his sight. Macular degeneration. I treated it before he regained consciousness."

The captain lifted an eyebrow. "Treatment without consent, Doctor?"

She sighed. "If I'd thought there was any hope of getting his consent, Captain, I'd have waited and asked for it." With a second, heavier sigh she turned away and brought up a screen on the desk monitor. "This is his genetic code. I've tried to find a match in the Missing Persons files, going back over a hundred years. Nothing."

"More mystery," remarked Will.

"But he's definitely human. And there's one thing I found that I think you should see." Moving slowly, she crossed to the bed. The others followed her, staying back a little to reduce the apparent threat. The growls from the prisoner increased in volume, his yellowed teeth showing. His eyes watched her malignantly.

"I'm not going to hurt you." Her voice was soothing, but it had no visible effect. As her hand reached towards his chest, he lunged at her. The snick of his teeth closing on empty air was a testament to her quick reactions, but she'd plainly been expecting the attempt to bite; she simply evaded the snap, and pulled down the sheet as far as his waist.

His chest was partly covered by the skins in which he was still clad. But on his right breast there was a small, clumsily executed tattoo: a sharply angled arrowhead, forming a shape eerily similar to the insignia on the personal communicator each of them was wearing.

"Starfleet!" Deanna stared incredulously at it.

"It could be just a coincidence." With the appropriate care to avoid the second snap, the doctor replaced the blanket.

"But it seems we have no way of establishing whether it is or not." Jean-Luc frowned. Bringing the man up from the planet had seemed the only possible course at the time, but he was beginning to wonder what it had achieved. They had been trying to rescue him as well to satisfy their own inevitable curiosity, but the object of both was clearly unable to understand that they meant him no harm. He might not even be capable of associating his miraculously improved vision with them in any way, and in the meantime he was suffering extreme mental trauma from his imprisonment.

"Counsellor," he said finally, "do you think it would help the situation if he no longer felt himself to be a prisoner? Do you think that would help us to gain his trust?"

"It couldn't hurt." She gazed at the old man thoughtfully. "I don't think anyone who woke up unable to move, in a strange place among strange people, could possibly be expected to think they were friendly."

"The question I have to ask is, how friendly is he," Katherine interjected dryly. "An ordinary human mouth is full of bacteria, even given proper oral care. I wouldn't care to speculate on what's thriving in his. And as you saw just then, Captain, his response to the unknown is 'bite first and ask questions later'."

"He might be less inclined to bite if he felt he had alternative options," suggested Will. "If we provided him with somewhere he could hide in till he realises we aren't going to hurt him."

Katherine exhaled doubtfully, but Jean-Luc felt the idea had merit. It required a little ingenuity and some rearrangement of Sickbay's furniture, but presently a couple of chairs, a few spare sheets and some temporary adhesive made a 'den' in one corner.

The risks inherent in the situation meant that Worf would of necessity be present. Informed of the plan, he frowned doubtfully, but stood to one side, ready to intervene if giving the stranger freedom invited violence against any of Enterprise's crew – a development that from his expression he clearly thought all too likely. ("But bear in mind his age, please, Lieutenant," the doctor requested; a stricture that brought a slightly insulted frown to the warrior's face.)

It was obvious that the patient reserved a particular distrust for the Klingon, at whom he had glared and growled since his advent. Jean-Luc admired the cunning and deftness with which Katherine took advantage of his preoccupation with the new arrival to slip in and click open the restraints, slipping off the sheet to emphasise that he was now free to move if he chose.

He certainly did choose. He darted for the den as quickly as his legs could carry him – moving with surprising agility, given his age – and disappeared inside it. A crescendo of snarls defied anyone to follow him inside; all that could now be seen of him now was his feet, suggesting he was tucked as far into the corner as he could go.

"Well, at least he didn't try to attack anyone." There was more than a note of relief in Riker's voice. "Deanna, has that helped any?"

"Not a great deal. I think he's very confused. I'd imagine the best thing would be to leave him alone for a while and let him settle down."

"Not unsupervised," Worf rumbled, and stepped to the comm panel to summon a member of Security .

"No, perhaps that would not be advisable," the captain agreed. "Very well. Doctor, do you have any objections?"

She glanced at the den. "He needs to relax. I don't think there's much danger of him coming out anytime soon. Yes, Captain, leave him here. As long as I have a guard I can call on if needs be."

"I will appoint someone to be on duty at all times," the Klingon nodded, and at that moment the guard he had summoned arrived and was given orders to ensure that the visitor posed no danger to the doctor or anyone else who visited Sickbay.

Worf said no more as he accompanied the captain and XO to the Bridge, but he was still frowning. "Captain," he said presently, as the turbo-lift slowed to a halt, "have you formulated any plans as to what we intend to do with this person?"

"I'm afraid I haven't got quite that far," Jean-Luc replied as the turbo-lift doors hissed back . "But until or unless we manage to establish his identity, or manage to establish even some form of communication with him, it would appear inhumane in the extreme to simply remove him from the world he probably thinks of as his home – however primitive his living conditions there happen to be."

Data turned from his station. "I believe, Captain, that I may be able to assist with the former."

"Proceed, by all means, Commander!"

Unexpectedly, however, the android hesitated. "I believe, sir, the matter should be discussed in privacy."

The slight sense of unease that had lain in the captain's stomach since the first sight of the dishevelled figure deepened. He gestured to his Ready Room. "You too, Number One."

He took a seat at his desk, and Will moved to stand beside and slightly behind him.

Data took up station in front of the desk, facing them both. "On being informed by Doctor Pulaski that she was unable to trace our visitor's DNA within the last century, I took the liberty of searching the Starfleet archives, where I found a positive match. I can now state unequivocally who this man's parents were: Lieutenant Malcolm Reed and Ensign Hoshi Sato, both officers who served on board the Enterprise NX-01."