Reaching up, he turned to Anglesey’s alpha. His own had a somewhat lower frequency, it was necessary to carry the signals through a heterodyning process. Still no reception. Well, of course he had to find the exact wave form, timbre was as basic to thought as to music. He adjusted the dials slowly, with enormous care.

Something flashed through his consciousness, a vision of clouds roiled in a violet-red sky, a wind that galloped across horizonless immensity—he lost it. His fingers shook as he turned back.

The psibeam between Joe and Anglesey broadened. It took Cornelius into the circuit. He looked through Joe’s eyes, he stood on a hill and stared into the sky above the ice mountains, straining for sign of the first rocket; and simultaneously he was still Jan Cornelius, blurrily seeing the meters, probing about for emotions, symbols, any key to the locked terror in Anglesey’s soul.

The terror rose up and struck him in the face.

Psionic detection is not a matter of passive listening in. Much as a radio receiver is necessarily also a weak transmitter, the nervous system in resonance with a source of psionic-spectrum energy is itself emitting. Normally, of course, this effect is unimportant; but when you pass the impulses, either way, through a set of heterodyning and amplifying units, with a high negative feedback…

In the early days, psionic psychotherapy vitiated itself because the amplified thoughts of one man, entering the brain of another, would combine with the latter’s own neural cycles according to the ordinary vector laws. The result was that both men felt the new beat frequencies as a nightmarish fluttering of their very thoughts. An analyst, trained into self-control, could ignore it; his patient could not, and reacted violently.

But eventually the basic human wave timbres were measured, and psionic therapy resumed. The modern esprojector analyzed an incoming signal and shifted its characteristics over to the “listener’s” pattern. The really different pulses of the transmitting brain, those which could not possibly be mapped onto the pattern of the receiving neurons—as an exponential signal cannot very practicably be mapped onto a sinusoid—those were filtered out.

Thus compensated, the other thought could be apprehended as comfortably as one’s own. If the patient were on a psibeam circuit, a skilled operator could tune in without the patient being necessarily aware of it. The operator could either probe the other man’s thoughts or implant thoughts of his own.

Cornelius’ plan, an obvious one to any psionicist, had depended on this. He would receive from an unwitting Anglesey-Joe. If his theory was right and the esman’s personality was being distorted into that of a monster, his thinking would be too alien to come through the filters. Cornelius would receive spottily or not at all. If his theory was wrong, and Anglesey was still Anglesey, he would receive only a normal human stream of consciousness and could probe for other troublemaking factors.

His brain roared!

What’s happening to me?

For a moment, the interference which turned his thoughts to saw-toothed gibberish struck him down with panic. He gulped for breath, there in the Jovian wind, and his dreadful dogs sensed the alienness in him and whined.