The look he gave the fat volume of Helo's Tables of Time Integrals did not sear the binding, to Ranin's great surprise.

The signal light flashed, and Haridin leaped to the door.

He snatched the package from the messenger's hand and ripped open the wrappings frantically.

He turned to the last page and stared at Santin's final note:

'Your calculations are correct. Congratulations - and won't this knock Porus's head right off his shoulders! Better get in touch with him at once.'

Ranin read it over the other's shoulder, and for one long minute the two gazed at each other.

'I was right,' whispered Haridin, eyes bulging. 'We've found something in which the imaginary doesn't square out. We've got a predicted reaction which includes an imaginary quantity!'

The other swallowed and brushed aside his stupefaction with an effort. 'How do you interpret it?'

'Great space! How in the galaxy should I know? We've got to get Porus, that's all.'

Ranin snapped his fingers and grabbed the other by the shoulders. 'Oh, no, we won't. This is our big chance. If we can carry this through, we're made for life.' He stuttered in his excitement. 'Arcturus! Any psychologist would sell his life twice over to have our opportunity right now.'

The Draconian squid crawled placidly about, unawed by the huge solenoid that surrounded its tank. The mass of tangled wires, the current leads, the mercury-vapor lamp up above meant nothing to it. It nibbled contentedly at the fronds of the sea fern about it and was at peace with the world.

Not so the two young psychologists. Eblo Ranin scurried through the complicated set-up in a last-minute effort at checking everything. Lor Haridin helped him in intervals between nail-biting.

'Everything's set,' said Ranin, and swabbed wearily at his damp brow. 'Let her shoot!'

The mercury-vapor!amp went on and Haridin pulled the window curtains together. In the cold red-less light, two green tinted faces watched the squid closely. It stirred restlessly, its warm pink changing to a dull black in the mercury light.

'Turn on the juice,' said Haridin hoarsely.

There was a soft click, and that was all.

'No reaction?' questioned Ranin, half to himself. And then he held his breath as the other bent closer.

'Something's happening to the squid. It seems to glow a bit -or is it my eyes?'

The glow became perceptible and then seemed to detach itself from the body of the animal and take on a spherical shape of itself. Long minutes passed.

'It's emitting some sort of radiation, field, force - whatever you want to call it - and there seems to be expansion with time.'

There was no answer, and none was expected. Again they waited and watched.

And then Ranin emitted a muffled cry and grasped Hari-din's elbow tightly. 'Crackling comets, what's it doing?'

The globular glowing sphere of v/hatever it was had thrust out a pseudopod. A gleaming little projection touched the swaying branch of the sea-fern, and where it touched the leaves turned brown and withered!

'Shut off the current!'

The current clicked off; the mercury-vapor lamp went out; the shades were parted and the two stared at each other nervously.

'What was it?'

Haridin shook his head. 'I don't know. It was something definitely insane. I never saw anything like it.'

'You never saw an imaginary in a reaction equation before, either, did you? As a matter of fact, I don't think that expanding field was any known form of energy at -'

His breath came out in one long whistling exhalation and he retreated slowly from the tank containing the squid. The mollusc was motionless, but around it half the fern in the tank hung sere and withered.

Haridin gasped. He pulled the shades and in the gloom, the globe of glowing haze bulked through half the tank. Little curving tentacles of light reached toward the remaining fern and one pulsing thread extended through the glass and was creeping along the table.

That fright in Ranin's voice rendered it a cracked, scarcely-understood sound.

'It's a lag reaction. Didn't you test it by Wilbon's Theorem?'

'How could I?' The other's heart pumped madly and his dry lips fought to form words. 'Wilbon's Theorem didn't make sense with an imaginary in the equation. I let it go.'

Ranin sped into action with feverish energy. He left the room and was back in a moment with a tiny, squealing, squirrel-like animal from his own lab. He dropped it in the path of the thread of light stealing along the table, and held it there with a yard rule.

The glowing thread wavered, seemed to sense the presence of life in some horribly blind way, and lunged toward it. The little rodent squealed once, a high-pitched shriek of infinite torture, and went limp. In two seconds it was a shriveled, shrunken travesty of its former self.

Ranin swore and dropped the rule with a sudden yell, for the thread of light - a bit brighter, a bit thicker - began creeping up the wood toward him.

'Here,' said Haridin, 'let's end this!' He yanked a drawer open and withdrew the chromium-plated Tonite gun within. Its sharp thin beam of purple light lunged forward toward the squid and exploded in blazing, soundless fury against the edge of the sphere of force. The psychologist shot again and again, and then compressed the trigger to form one continuous purple stream of destruction that ceased only when power failed.

And the glowing sphere remained unharmed. It engulfed the entire tank. The ferns were brown masses of death.

'Get the Board,' yelled Ranin. 'It's beyond us entirely!'

There was no confusion - humanoids in the mass are simply not subject to panic, if you don't count the half-genius, half-humanoid inhabitants of the planets of Sol - and the evacuation of the University grounds was carried out smoothly.

'One fool,' said old Mir Deana, ace physicist of Arcturus U., 'can ask more questions than a thousand wise men can answer.' He fingered his scraggly beard and his button nose sniffed loudly in disdain.

'What do you mean by that?' questioned Frian Obel sharply. His green Vegan skin darkened angrily.

'Just that, by analogy, one cosmic fool of a psychologist can make a bigger mess than a thousand physicists can clear up.'

Obel drew in his breath dangerously. He had his own opinion of Haridin and Ranin, but no lame-brain psysicist could -

The plump figure of Qual Wynn, university president, came charging down upon them. He was out of breath and spoke between puffs.

'I've gotten in touch with the Galactic Congress and they're arranging for evacuation of all Eron, if necessary.' His voice became pleading. 'Isn't there anything that can be done?'

Mir Deana sighed, 'Nothing - yet! All we know is this: the squid is emitting some sort of pseudo-living radiatory field which is not electromagnetic in character. Its advance cannot be stopped by anything we have yet tried, material or vacuum. None of our weapons affect it, for within the field the ordinary attributes of space-time apparently don't hold.'

The president shook a worried head. 'Bad, bad! You've sent for Porus, though?' He sounded as though he were clutching at a last straw.

'Yes,' scowled Frian Obel. 'He's the only one that really knows that squid. If he can't help us, no one can.' He stared off toward the gleaming white of the university buildings, where the grass over half the campus was brown stubble and the trees blasted ruins.

'Do you think,' said the president, turning to Deana once more, 'that the field can span interplanetary space?'

'Sizzling novae, I don't know what to think!' Deana exploded, and he turned pettishly away.

There was a thick silence of utter gloom.

Tan Porus was sunk in deep apathy. He was unaware of the brilliant coruscations of color overhead. He didn't hear a sound of the melodious tones that filled the auditorium.