He shrugged. “Imagination! Mustn’t get nervy now.”

There was the vaguest glitter-a sparkle that was felt rather than seen-in the air about him. And then it invaded the ship itself, and, looking up, the Rigellian saw the five Eronian ricebirds he had brought with him lying dead on the floor of their cage, huddled masses of bedraggled feathers.

“The ‘death field’ is in,” he whispered. It had penetrated the steel hull of the cruiser.

The cruiser bumped to a rather unskillful landing on the broad university athletic field, and Tan Porus, an incongruous figure in the bulky osmium suit, stepped out. He surveyed his depressing surroundings. From the brown stubble underfoot to the glimmering haze that hid the normal blue of the sky, all seemed-dead.

He entered Psychology Hall.

His lab was dark; the shades were still drawn. He parted them and studied the squid’s tank. The water replenisher was still working, for the tank was full. However, that was the only normal thing about it. Only a few dark-brown, ragged strands of rot were left of what had once been sea-fern. The squid itself lay inertly upon the floor of the tank.

Tan Porus sighed. He felt tired and numbed. His mind was hazy and unclear. For long minutes he stared about him unseeingly.

Then, with an effort, he raised the bottle he held and glanced at the label-12 molar hydrochloric acid.

He mumbled vaguely to himself. “Two hundred cc. Just dump the whole thing in. That’ll force the pH down-if only hydrogen ion activity means something here.”

He was fumbling with the glass stopper, and-suddenly- laughing. He had felt exactly like this the one and only time he had ever been drunk.

He shook the gathering cobwebs from his brain. “Only got a few minutes to do-to do what? I don’t know-something anyway. Dump this thing in. Dump it in. Dump! Dump! Dumpety-dump!” He was mumbling a silly popular song to himself as the acid gurgled its way into the open tank.

Tan Porus felt pleased with himself and he laughed. He stirred the water with his mailed fist and laughed some more. He was still singing that song.

And then he became aware of a subtle change in environment He fumbled for it and stopped singing. And then it hit him with the suddenness of a downpour of cold water. The glitter in the atmosphere had gone!

With a sudden motion, he unclasped the helmet and cast it off. He drew in long breaths of air, a bit musty, but unkilling.

He had acidified the water of the tank, and destroyed the field at its source. Chalk up another victory for the pure mathematics of psychology!

He stepped out of his osmium suit and stretched. The pressure on his chest reminded him of something. Withdrawing the booklet his wife had dropped, he said, “The talisman came through!” and smiled indulgently at his own whimsy.

The smile froze as he saw for the first time the title upon the book.

The title was Intermediate Course in Applied Psychology- Volume 5 .

It was as if something large and heavy had suddenly fallen onto Porus’s head and driven understanding into it Nina had been boning up on applied psych for two whole years .

This was the missing factor. He could allow for it. He would have to use triple time integrals, but-

He threw the communicator switch and waited for contact

“Hello! This is Porus! Come on in, all of you! The death field is gone! I’ve beaten the squid.” He broke contact and added triumphantly, “-and my wife!”

Strangely enough-or, perhaps, not so strangely-it was the latter feat that pleased him more.

 The chief interest to me in “The Imaginary” is that it foreshadows the “psychohistory” that was to play such a big role in the “Foundation” series. It was in this story and in its predecessor, “Homo Sol,” that for the first time I treated psychology as a mathematically refined science.

 It was about time that I made another stab at Unknown , and I did so with a story called “The Oak,” which, as I recall, was something about an oak tree that served as an oracle and delivered ambiguous statements. I submitted it to Campbell on July 16, 1940, and it was promptly rejected.

 One of the bad things about writing for Unknown was that the magazine was one of a kind. If Unknown rejected a story, there was no place else to submit it. It was possible to try Weird Tales , a magazine that was older than any science fiction magazine, but it dealt with old-fashioned, creaky horror tales and paid very little to boot. I wasn’t really interested in trying to get into it. (And besides, they rejected both “Life Before Birth” and “The Oak” when I submitted them.)

 Still, July 29, 1940, was a turning point in my career, although, of course, I had no way of telling it. I had up to that point written twenty-two stories in twenty-five months. Of these I had sold (or was to sell) thirteen, while nine never sold at all and no longer exist. The record wasn’t abysmal but neither was it great-let’s call it mediocre.

 However, as it happened, except for two short-short stories that were special cases, I never again wrote a science fiction story I could not sell. I had found the range.

 But not Campbell’s range particularly. In August I wrote “Heredity,” which I submitted to Campbell on August 15, and which he rejected two weeks later. Fortunately, Pohl snapped it up at once.