There was no answer at first. Then Zira said, “Of course we can. The others don’t want to while you’re here. Will you leave us alone for a minute?”

“Ye gods!” Lewis said. He motioned to the keeper who was standing as if carved from stone. They left the cage, locking it carefully behind them. “Come on, Stevie,” Lewis said.

“Do you think it is wise to leave them?” she asked. She struggled to her feet, surprised at how hard it was to stand.

“Yes. Now come on.” He put his arm around her waist as they went out the door at the end of the hall. The door closed behind them.

There was a long silence. “They may be listening to us,” Cornelius said at last.

“Nonsense,” Zira snorted. “If they knew how to make it possible to listen to us, they already knew we could talk. It is time we told them everything.”

Milo studied Zira’s face intently as he said, “Zira, are you mad?”

“Dr. Milo, please do not call my wife mad.”

“I did not call her mad, Professor Cornelius. I merely asked her if she had gone mad. And I repeat the question. Zira, are you mad?”

“No. But I hate deceit.”

“So do I,” Milo replied. “But there is a time for truth and a time, not for lies, but for silence. Until we know who is our friend and who is our enemy—”

“And how in God’s name do we find out if we won’t communicate?” Zira demanded. “We can speak. So I spoke.”

“We can also listen,” Milo said.

“No longer,” Cornelius reminded them. “Besides, did you not see the interest Dr. Lewis took in us? He already suspected something. He goaded Zira into making that staircase. With words. Already he half expected her to understand him. And Milo, what do we hear when we listen? A lot of psychiatric small talk.”

“We can also observe—”

“A display of primitive apparatus.”

“Primitive?” Zira gave the table a vicious kick. “It’s prehistoric. This junk wouldn’t test the intelligence of a newt.” She kicked the display again, and a leg fell off the table.

“Zira, for God’s sake, be calm,” Cornelius protested.

“I am calm.” She continued to kick the apparatus. “Why should I be upset? Our world is gone. We’re trapped here among primitive humans, possibly the only intelligent apes in the universe, and we’re locked in a cage that stinks of gorilla! Why shouldn’t I be calm? I am calm!” She delivered another vicious kick.

“Now you’ve disturbed Milo,” Cornelius said, fighting to remain calm himself.

Milo screwed his clenched fists into his eyes as he paced in frustration. He walked as far from the other two as he could, until he was stopped by the bars separating their cage from the gorilla. Then he faced them angrily. “For God’s sake, stop fighting! It’s too late anyway. Now they know. We’ve got to think what we ought to tell them.”

“You don’t have to shout at me!” Zira snapped.

“I am NOT SHOUTING!” Milo shouted. He shook himself. More quietly, he said “Use your heads and start thinking.”

“Milo, look out!” Cornelius shouted. He rushed forward, but not in time. The gorilla in the next cage had reached through the bars and seized Milo. It held him against the bars and laughed.

“MILO-O-O-O!” Zira screamed. “Milo! Cornelius, help him!”

The door opened and Lewis Dixon came in. He saw the situation and shouted to the keeper. “Get your pistol, Jim! Quick!” Dixon rushed forward to the gorilla cage and began to open the door. He waved to distract the gorilla, shouted, anything to make it release the chimpanzee. It did nothing, but continued to hold Milo, squeezing tighter, not moving.

“He’s killing him!” Zira shouted. The two chimpanzees were trying to pull the gorilla’s hands away from Milo’s throat. “We’re not strong enough!”

Jim Haskins came up with a .32 automatic. He looked on in confusion.

“Shoot, Jim!” Dixon commanded.

“That’s a valuable animal,” Haskins protested. He stood there, paralyzed.

“Damn it, so are the chimps!” Dixon screamed. “Shoot the damned gorilla!”

Jim shuffled about in indecision. The two Marines had rushed into the room and stood outside the cage, uncertain of what to do.

“Shoot the gorilla!” Dixon commanded.

One of the Marines raised his rifle. He fired, slowly, three times. Bright splotches appeared on the gorilla’s chest. It looked up, surprised, but it did not release Milo.

“Again!” Dixon ordered.

Jim Haskins came into the cage. With a sad look he placed his pistol against the gorilla’s head and fired. The shot was not very loud after the blast of the Marine’s rifle.

The gorilla convulsed and staggered backward, his grip about Milo’s neck relaxed at last.

Milo fell in a shapeless heap. He did not move.

SIX

Dr. Lewis Dixon walked along with the white-coated attendants carrying away the body of the chimpanzee the others called “Milo.” Lewis grimaced involuntarily as he looked at the strangled body, and glanced up at Stevie. She was ashen, and still shaking.

“We’ll need a full dissection,” Lewis said. He kept his voice deliberately low so that the other chimps wouldn’t hear.

“Yes,” Stephanie said. “With a great deal of attention to the temporal lobes and speech centers.”

“But don’t start just yet,” Lewis continued. “Don’t disturb anything until we can get the gross anatomy. Keep him in cold storage until I can get there.”

“Yes, sir.” The attendants went out of the hospital wing of the zoo, and Lewis took Stephanie’s hand. He led her back to the chimpanzee cage. The door stood open, and they went inside.

Zira sat huddled against Cornelius. She sobbed against his shoulder, as Cornelius gently stroked her back.

“We mean you no harm,” Lewis said. There was no response from the apes. “Do you understand? We mean you no harm.”

Zira looked up in rage. She pointed to the dead gorilla in the next cage.

“But he isn’t us,” Lewis protested. “He’s your own kind.”

“He’s a gorilla,” Zira snapped. She leaped to her feet. “They’re all alike, killers. We are not gorillas!”

“I’m sorry,” Lewis said. “I meant he’s of your own genus. He’s an ape. Anyway, you needn’t be afraid of him any longer. The army men shot him.”

“Poetic justice,” Cornelius said.

“I beg your pardon?” Lewis said automatically. He winced slightly at the thought of begging an ape’s pardon. “I don’t think I understood.”

“In—uh, our world,” Cornelius said, “gorillas are the army.”

“And humans are their usual enemies,” Zira finished.

“Zira!” Cornelius warned.

Lewis and Stephanie looked at the apes in astonishment. “Perhaps you had better explain that,” Lewis said.

“They called you both ‘Doctor’,” Zira said. “Are you medical people?”

“We specialize in animal behavior,” Stevie said. “I’m a psychologist. Lewis is a psychiatrist.”

“So am I,” Zira said.

The two humans stepped back as if struck. Finally Lewis said, “All right. If you say so.”

“The question is,” Zira asked, “do you have the same professional customs as we? Are doctor-patient conversations always confidential?”

“Yes,” Lewis said. Stevie nodded.

“And are we your patients?” Zira continued.

Lewis looked thoughtful. “I’ve never thought of professional ethics as involving animal patients,” he said carefully. “But yes. Of course. Stevie?”

She nodded, the skin around her blue eyes creased with tiny lines. She looked puzzled, but said nothing.

“Certainly,” Lewis repeated. “And we still mean you no harm.”

“We realize that,” Cornelius said.

“But—” Zira protested.

“Nonsense, my dear. What have we to lose? We must trust someone. Why not our physicians?”

“That’s better,” Lewis said. Jim Haskins came back into the hospital wing, but Lewis waved him out. He waited until they were alone again. “Do you have a name?” he asked.