"Why'd we turn off here?" asked Northen. "Thought we were headed for Regional.""No telephones," said Ainsworthy, swinging between the stone gateposts of the drive to the Center. "Have to alert them." He was gratified that Northen fell immediately into the almost silent role of observer and kept his thoughts to himself.Kemble met them at the door. "KVIN?" he asked, reading Ainsworthy's sober face."Yes," said Ainsworthy. "It's Kief. You probably heard the Healiocopter. Who's available?""Providentially, the workers are all in from the fields." Kemble stepped back inside the Center, and, tugging the bell rope that hung just inside the door, swung the bell into voice. Ten minutes later he spoke from the Center porch to the crowd that had gathered from the stone and log houses that, with the Center, formed a hollow square of buildings backed by the neat home vegetable gardens, backed in their turn by wood lands and the scattered areas where each family grew its field and cash crops."KVIN," said Kemble. "Who's available?"Quickly a sub-group formed, more than twice as many as were needed if all were accepted. The others scattered back to their individual pursuits. Kemble gathered the donors together, briefly, speaking so quietly that Northen rumbled to Ainsworthy, "What's he saying? What's going on?""They always pray before any important project," said Ainsworthy neutrally."Pray!" Northen crumpled his notebook impatiently. "Wasting time. How they going to get to Regional? One hoss shay?""Relax!" snapped Ainsworthy, defensive for his friends. "These people have been personally involved in KVIN lots longer than you have. And they're going nowhere." Kemble turned back to Ainsworthy and accepted calmly the introduction to Northen, reading his attitude in a glance and smiling faintly over it at Ainsworthy. He excused himself and called, "Justin, you're co-ordinator today."Most of the interior of the Center was one huge room, since it served asmeeting and activity center for the settlement. Under Justin's direction, closet doors were opened, cots were unfolded and arranged in neat rows down the hall. Equipment was set up, lines of donors were formed, and everything was in readiness by the time the Bloodmobile clacked out of the sky and pummeled the grass in the hollow square with the tumult of its rotors.One by one the donors were given essential checks by means of a small meter applied to an ear lobe, and were accepted or rejected with quick efficiency.Northen stood glowering at the scene of quiet activity. "Why can't they go to Regional like any other humans?""Any particular reason why they should?" asked Ainsworthy shortly. "They're a willing, never-failing source, and have been since our Unit was established. Why shouldn't we cater to them? It doesn't jeopardize any of our operations."For a moment longer they watched the quiet rows of cots and their intent occupants, then Northen, with a grimace of annoyance, turned away. "Let's get to Regional," he said. "I want to follow this through, inch by inch.""But there's got to be a difference!" Red-faced and roaring, Northen thumped on the desk in Isolation at Regional. "There's got to be! Why else do KVIN's recover here?""You tell us." Dr. Manson moved back in distaste from Northen's thrust-out face. "That's your job. Find out why. We've researched this problem for ten years now. You tell us what we have overlooked or neglected. We will receive with utmost enthusiasm any suggestions you might have. According to exhaustive tests from every possible point of reference, there is no difference in the blood of these donors and any donors anywhere!" He did a slight thumping of his own, his thin face flushed with anger. "And KVIN is KVIN, no matter where!""I don't like it," Northen growled to Ainsworthy a few days later, "Kief's convalescent now, but why? I've been drawing up another set of statistics and I don't like it.""Must you like it?" asked Ainsworthy. "Is that requisite to valid results?""Of course not," growled Northen morosely."What statistics?" Ainsworthy asked, interest quickening. "A new lead?""It's true, isn't it, that the only blood donors used for KVIN replacements are those from Away?""Yes," nodded Ainsworthy."That's a factor that hasn't been considered before," said Northen. "I've queried the other Regionals-and I don't like it. There are no Detach donors involved at San Fran Regional. At Denver Regional, half their donors are Detaches." His thick hands crumpled the papers he held. "And curse'n'blastit! All the Central Regional donors are Detached"Ainsworthy leaned back and laughed. "Exactly the ratio of deaths and recoveries regionally. But why are you so angry? Will it kill you if a Detach has something to do with solving our difficulty?""It's that those lumpheaded-sons-of-bowlegged-sea-cooks at Central swear there's nothing in the blood of any of these Detaches that's any different from any other donors! And the benighted-fuzzlebrains at Denver swear the same!""Hoh!" Ainsworthy leaned forward. "No answer?" he chuckled. "Maybe it's an invalid question. Maybe no one recovers from KVIN!""Don't be more of a fool than you have to," snapped Northern. Then automatically, "Your pardon.""It's yours," Ainsworthy automatically responded.The two sat in silence for a moment, then Northen pushed himself slowly to his feet. "Well, let's go see this-who's he? The Away fellow." "Kemble," said-Ainsworthy, rising."Yes, Kemble." Northen knocked his chair back from the table as he turned. "Maybe he can give us some sort of lead." Kemble was in the fields when they arrived so they had a couple of hours to kill before he could talk with them. They spent the time in touring the settlement, each aspect of which only deepened Northen's dislike of the place. They ended up at the tiny school where girls, long-braided, full-skirted, and boys, barefooted for the warm day and long trousered in the manner of Detaches, worked diligently and self-consciously under the visitors' eyes.After they left the school, Northen snorted. "They're no angels! Did you see that little devil in the back seat slipping that frog down into the little girl's desk drawer?"Ainsworthy laughed. "Yes," he said. "He was very adroit. But where did you get the idea that Detaches are supposed to be angels? They certainly never claim such distinction.""Then why do they feel the world's so evil that they have to leave it?" snapped Northen."That's not the reason-" Ainsworthy broke off, weary to the bone of this recurrent theme harped on by those who dislike the Detaches. Well, those who took refuge in such a reaction were only striking back at a group that, to them, dishonored their own way of life by the simple act of withdrawing from it.Kemble met them in a small office of the Center, his hair still glistening from his after-work wash-up. He made them welcome and said, "How can I help you?"Northen stated his problem succinctly, surprising Ainsworthy by his being able to divorce it from all emotional bias. "So it comes down to this," he finished. "Are you in possession of any facts, or, lacking facts, any theories that might have a bearing on the problem?"There was a brief silence, then Kemble spoke. "I'm surprised, frankly, at these statistics. It never occurred to me that we Detaches were involved in KVIN other than purely incidentally. As a matter of fact, we have no connection with the other Detach settlements. I mean, there's no organization as such of Detaches. Each settlement is entirely independent of any other, except, perhaps, in that a certain type of personality is attracted to this kind of life. We exchange news and views, but there are no closer ties.""Then there wouldn't be any dietary rules or customs-"