Shrill screams rent the air as early visitors at the zoo scampered for safety.
Animal voices added to the uproar.
The elephant, turning from his original direction, charged through the two acre paddock in which three pairs of wolves were kept, taking fence, trees and brush in his stride.
On the steps of the administration building. Riggs looked back.
Nero, the lion, was dripping water! The water that theoretically should have kept him penned in his cage as securely as steel bars!
A keeper, armed with a rifle, rushed up to Riggs.
“All hell’s broken loose,” he shouted.
The polar bears had staged a bloody battle, with two of them dead, two dying and the rest so badly mauled that there was little hope they would live. Two buck deer, with locked horns, were fighting to the death. Monkey Island was in an uproar, with half of the little creatures mysteriously dead—dead, the keepers said, of too much excitement. A nervous condition.
“It ain’t natural,” protested Pop, when they were inside. “Animals don’t fight like that.”
Riggs was yelling into a telephone.
Outside a rifle roared.
Pop flinched.
“Maybe that’s Nero,” he groaned. “Nero, that I raised from a cub. Bottle-fed him, I did.”
There were traces of tears in the old man’s eyes.
It was Nero. But Nero, before he died, had reached out for the man who held the rifle and had killed him with a single vicious blow that crushed his skull.
Later that day, in his office, Doctor Gilmer smote the newspaper that lay open on his desk.
“You see that?” he asked Jack Woods.
The reporter nodded grimly. “I see it. I wrote it. I worked on it all afternoon. Wild animals turned loose in the city. Ravening animals. Mad with the lust to kill. Hospitals full of dying people. Morgues with ripped humanity. I saw an elephant trample a man into the earth before the police shot the beast. The whole zoo gone mad. Like a jungle nightmare.”
He wiped his forehead with his coat sleeve and lit a cigarette with shaking fingers.
“I can stand most anything,” he said, “but this was the acme of something or other. It was pretty horrible, Doc. I felt sorry for the animals, too,” he said. “Poor devils. They weren’t themselves. It was a pity to have to kill so many of them.”
Doc leaned across the table. “Why did you come here?” he asked.
Woods nodded toward the glass cage that held the Martian animal. “I got to thinking,” he said. “The shambles down there today reminded me of something else—”
He paused and looked squarely at Gilmer.
“It reminded me of what we found in the Hello Mars IV.”
“Why?” snapped Gilmer.
“The men on board the ship were insane,” declared Woods. “Only insane men would do the things they did. And Cooper died a maniac. How he held onto his reason long enough to bring the ship to a landing is more than I know.”
Gilmer took the mangled cigar out of his mouth and concentrated on picking off the worst of the frayed edge. He tucked it carefully back into the corner of his jaw.
“You figured those animals were insane today?”
Woods nodded.
“And for no reason,” he added.
“So you up and suspicioned the Martian animal,” said Gilmer. “Just how in blue hell do you think that defenseless little Fur-Ball over there could make men and animals go insane?”
“Listen,” said Woods, “don’t act that way, Doc. You’re on the trail of something. You broke a poker date tonight to stay here at the laboratory. You had two tanks of carbon monoxide sent up. You were shut in here all afternoon. You borrowed some stuff from Appleman down in the sound laboratory. It all adds up to something. Better tell me.”
“Damn you,” said Gilmer, “you’d find it out anyway even if I kept mum.”
He sat down and put his feet on the desk. He threw the wrecked and battered cigar into the waste-paper basket, took a fresh one out of a box, gave it a few preliminary chews and lit it.
“Tonight,” said Gilmer, “I am going to stage an execution. I feel badly about it, but probably it is an act of mercy.”
“You mean,” gasped Jack, “that you are going to kill Fur-Ball over there?”
Gilmer nodded. “That’s what the carbon monoxide is for. Introduce it into the cage. He’ll never know what happened. Get drowsy, go to sleep, never wake up. Humane way to kill the thing.”
“But why?”
“Listen to me,” said Gilmer. “You’ve heard of ultrasonics, haven’t you?”
“Sounds pitched too high for the human ear to hear,” said Woods. “We use them for lots of things. For underwater signaling and surveying. To keep check on high-speed machines, warn of incipient breakdowns.”
“Man has gone a long way with ultrasonics,” said Gilmer. “Makes sound do all sorts of tricks. Creates ultrasonics up to as high as 20 million vibrations per second. One million cycle stuff kills germs. Some insects talk to one another with 32,000 cycle vibration. Twenty thousand is about as high as the human ear can detect. But man hasn’t started yet. Because little Fur-Ball over there talks with ultrasonics that approximate thirty million cycles.”
The cigar traveled east to west.
“High frequency sound can be directed in narrow beams, reflected like light, controlled. Most of our control has been in liquids. We know that a dense medium is necessary for the best control of ultrasonics. Get high frequency sound in a medium like air and it breaks down fast, dissipates. That is, up to twenty million cycles, as far as we have gone.
“But thirty million cycles, apparently, can be controlled in air, in a medium less dense than our atmosphere. Just what the difference is I can’t imagine, although there must be an explanation. Something like that would be needed for audible communication on a place like Mars, where the atmosphere must be close to a vacuum.”
“Fur-Ball used thirty million cycle stuff to talk with,” said Jack. “That much is clear. What’s the connection?”
“This,” said Gilmer. “Although sound reaching that frequency can’t be heard in the sense that your auditory nerves will pick it up and relay it to your brain, it apparently can make direct impact on the brain. When it does that it must do something to the brain. It must disarrange the brain, give it a murderous complex, drive the entity of the brain insane.”
Jack leaned forward breathlessly.
“Then that was what happened on the Hello Mars IV. That is what happened down in the park today.”
Gilmer nodded, slowly, sadly.
“It wasn’t malicious,” he said. “I am sure of that. Fur-Ball didn’t want to hurt anything. He was just lonesome and a little frightened. He was trying to contact some intelligence. Trying to talk with something. He was asleep or at least physiologically dormant when I took him from the ship. Probably he fell into his sleep just in time to save Cooper from the full effects of the ultrasonics. Maybe he would sleep a lot. Good way to conserve energy.
“He woke up sometime yesterday, but it seemed to take some time for him to get fully awake. I detected slight vibrations from him all day yesterday. This morning the vibrations became stronger. I had put several different assortments of food in the cage, hoping he would choose one or more to eat, give me some clue to his diet. But he didn’t do any eating, although he moved around a little bit. Pretty slow, although I imagine it was fast for him. The vibrations kept getting stronger. That was when the real hell broke out down in the zoo. He seems to be dozing off again now and things have quieted down.”