A stewardess, clad in the chic BOAC uniform, moved down the aisle, quietly informing the passengers that they could have coffee served at their seats or take breakfast in the lounge. The atmosphere of the plane's interior was filled with the low murmur of a hundred conversations against the background of the susurrant mutter of the mighty engines. _Uhhh--uh--uh--dizzy--head hurts--uh--uh--_ The sounds in the plane altered subtly as the faint thought insinuated itself on every brain inside the aircraft. None of the Normal passengers recognized it for what it was; it was too gentle, too weak, to be recognized directly by their minds. But David Houston recognized it instantly for what it was. Somewhere on the plane, a Controller had been unconscious. _Had_ been. For now, his powerful mind was trying to swim up from the black depths of nothingness. _Uh--uhhhh--uhh--_ The Normal passengers became uneasy, not knowing why they were disturbed. To them, it was like a vaguely unpleasant but totally unrecognizable nudge from their own subconscious, like some long-forgotten and deeply buried memory that had been forced down into oblivion and was now trying to obtrude itself on the conscious mind. _Uhhh--Oooohh--where?--what happened?--_ A fully conscious telepath could project his thoughts along a narrow locus, focusing them on a single brain, leaving all other brains oblivious to his thoughts. Like a TV broadcasting station, he could choose his wavelength and stick to it. But a half-conscious Controller sprayed his thoughts at random, creating mental disturbances in his vicinity. Like a thunderstorm creating radio static, there was no selectivity. Savagely, David Houston did what he had to do. It might be a trap, but he had to avoid the carnage that might follow if this went on. He hurled a beam of thought, hard-held, at the offending mind of the awakening telepath. _DON'T THINK! RELAX!_ Normally it was impossible for a Controller to take over the mind of another Controller, but these were abnormal circumstances; the half-conscious man, whoever he was, was weakened mentally by some kind of enforced unconsciousness--either a drug or a stun gun. Houston took over his mind smoothly and easily. _Robert Harris!_ Houston recognized the mind as soon as he held it. He didn't try to force anything on Harris's mind; he simply held it, cradling it, helping Harris to regain consciousness easily, bringing him up from the darkness gently. In normal sleep, everyone's mind retains a certain amount of self-control and awareness of environment. If it didn't, noise and bright lights wouldn't awaken a sleeping person. * * * * * In normal sleep, a telepath retained enough control to keep his thoughts to himself, even when waking up.