Zira almost answered. If the human hadn’t been so ugly, so manlike, she would have; but it always surprised her to hear humans talk. She had known only three who could. She felt ashamed of herself for slapping the keeper last night. How could he know she didn’t like bananas? He was only trying to be nice.

The man looked into all the cages, then went into the enclosure with the deer and did something Zira couldn’t see. It was obvious that the human liked animals. He seemed as civilized as any chimpanzee. As she watched him, Cornelius and Dr. Milo woke up.

Zira turned to her husband and said “Good morning.”

The keeper turned quickly from the sick deer. “Who’s there?” he said when no one answered, he wandered through the zoo hospital building, looking everywhere, and muttering.

“Quiet,” Cornelius whispered.

“I still think it’s the wrong idea,” Zira said. “We ought to talk to them.” She kept her voice low. The keeper finally went back to his sick deer. He was still shaking his head and muttering.

A few minutes later the doors opened again. Two humans in white coats came in. The male was about six feet tall, with sandy brown hair and the kind of square-jawed features that Zira associated with the more aggressive humans. The female was much shorter, with dark hair and eyes. The soldiers at the door followed her into the room and gazed at her for a time before they went back outside, and Zira deduced that they found her very attractive. She had never understood human standards of beauty.

“Good morning, Dr. Dixon,” the keeper said.

“Morning, Jim. This is my new assistant. Dr. Stephanie Branton. Stevie, meet Jim Haskins. He’s a better animal psychiatrist than I am.”

The humans chattered together for a long time. Two soldiers brought a desk and some tables into the corridor outside the cages, then brought in crates of apparatus. Zira watched with interest. The equipment was unfamiliar, but extremely well made, and she felt envy. If she could have had some of her designs built that well . . .

All three apes watched as the humans set up their apparatus. Dr. Milo was worried; what did these humans intend? Who were their friends and who their enemies?

It was quite possible, he thought, that they would have no friends at all.

FIVE

Dr. Lewis Dixon watched lazily as the zoo people set up his apparatus. He was by nature a careful man, but not a worrier; there was no point in driving himself crazy about how the chimpanzees got in Colonel Taylor’s space capsule. He would find out or he wouldn’t, and worrying was not going to help a bit.

He grinned at Stevie, and she smiled back. She had been with his team only about three weeks, and they were already half in love. He even had disturbing thoughts about orange blossoms and weddings. Lewis Dixon had always sworn that he would marry someone outside his profession; somebody with a life of her own, a different kind of career, so that they would have some common interests but different ones too. Stevie was making hash out of all his resolutions. She’d had the same idea, and she wasn’t having any more success than he was. He winked at her, and knew she was thinking the same things.

Stevie and Jim carried some of the equipment into the cage. “Female’s a little uppity,” Jim said. “Slapped me last night. Not hard, though.”

“Hey, be careful, Hon,” Lewis called.

“I will.” Stevie grinned. Lewis thought it a very nice grin. Good teeth. No future dental bills to pay.

The test apparatus was simple. A shade that could be raised and lowered divided a low table. The experimenter sat at one side, and the subject at the other. As Stevie and Jim set it up, Lewis observed the chimps through half-closed eyes.

They’d seen something like this before. He was certain of it. They were almost purposive in their attempts to ignore what Stephanie was doing. Lewis had never seen chimpanzees act that way before. But, he thought, I’ve never seen chimps wearing full pressure suits either. Or carrying a suitcase full of clothes, if I can believe that Navy flight surgeon. “They had to be trained to work some of the controls of that spacecraft,” Lewis said. “May as well make the first tests hard ones. These are probably very intelligent chimps.”

“All right,” Stephanie called.

“Try the female first,” Lewis said. “She keeps watching you. I think she wants to play.”

Jim led Zira to the screen. Stephanie lowered the screen to reveal a red cube. She raised the screen and placed a number of other objects with the cube: a red cone, a blue cube, red sphere, etc., then lowered it again. Zira promptly pointed to the red cube.

Stephanie smiled. “Very good.” She touched a button in the apparatus, and a compartment on Zira’s side opened. It had raisins, and the chimp ate them quickly, smacking her lips.

Lewis entered the cage, whistling softly to himself. “You can forget simple discrimination tests,” he said. “Those chimps are trained. Very well trained.”

“Sure about the others, Doctor Dixon?” Jim asked.

Lewis nodded. “I was watching them. They reacted when she reached for the cube. These chimps have been exposed to a lot of tests, Jim. We’d better make the next one tough.”

“Wonder if they can play games?” Stevie asked. She brushed long soft brown hair away from her eyes and put a hair clip back into place. “Tic-tac-toe? Some chimps can play it.”

Lewis shrugged. “That’s true. OK.”

They set an illuminated game board on the table. Stephanie handed Zira the stylus and nodded as the chimpanzee made a mark in the center square. “She knows the rules all right.”

“Try the male,” Lewis suggested. Jim took Cornelius by the hand and led him to the table.

Cornelius made a mark in the corner. Zira made another. Then Cornelius. Three moves later, Zira leaped up and held her hands clasped over her head, victorious boxer style. She chattered laughter.

“That settles that,” Lewis said. He took raisins from his pocket and gave them to Zira, then a smaller number to Cornelius. “Stevie, I’ve never heard of chimps who could play Tic-tac-toe by the rules. Not like that, waiting their turn to move—the best I’ve ever seen is a race to make three in a row. Those are the best trained chimpanzees I’ve ever heard of.”

“Is it just training, Lew? Couldn’t it be intelligence?”

“It’d be a whole order of magnitude higher than we expect of apes,” Lewis Dixon said. “OK. Let’s find out Kroeger’s test.”

“Sure.” Stephanie helped him attach a banana to the ceiling. The ladder was removed from the cage. Then several boxes and a stick were laid on the cage floor.

The three chimps stared at the boxes, up to the banana, and out to Lewis and Stevie.

“Maybe they aren’t hungry,” Jim said. “Fed ’em a lot last night.”

“I think they’re too stupid,” Lewis said. “They were only trained, not intelligent. As I thought.”

Zira snorted. One of the other chimps squalled. Zira looked at the boxes for a moment, then attached two together. She added others until they formed a staircase, and, with the pole, would let her reach the banana. Zira climbed to the top of the box, used the stick to touch the fruit, and climbed back down again.

“But why didn’t she get it?” Stevie asked.

Zira turned to the girl. “Because I loathe and detest bananas.” Her voice was very clear and carefully controlled.

Cornelius shouted: “Zira!”

Stephanie sat very carefully at the desk outside the cage.

“You all right?” Lewis asked. His own legs felt a little rubbery.

“Sure. It surprised me, that’s all. I don’t know why. It’s only a chimpanzee speaking English. We did hear that, didnt we, Lewis?” She continued to sit at the desk.

“We surely did,” Lewis said. He turned to the chimps. “Can all of you talk?”