Invasion

Motioning toward the building, the two former policemen went inside. Vince stayed outside and let his eyes roam around the horizon. It was so hot that he could see heat rising in the air.

The policemen came out quickly and shook their heads. She wasn't in there.

Vince motioned back to the copter. He was close. He could sense it. After all, how far could she get on foot in that heat?

Pitt came into the lab. Everyone was working so intently that they didn't even raise their heads.

"She's finally sleeping," he said.

"Did you lock the outer door?" Harlan asked.

"No," Pitt said. "Do you think I should?"

"Absolutely," Sheila said. "We don't want any surprises."

"I'll be right back," Pitt said. He returned to the air lock and looked in at Cassy. She was still sleeping peacefully. Her coughing had significantly abated. Pitt locked the door.

Returning to the lab, he took a seat. Again no one acknowledged him. Sheila was engrossed, inoculating tissue cultures with the enabling protein. Harlan was extracting more antibody. Jonathan was at a computer terminal wearing earphones and working a joystick.

Pitt asked Jonathan what he was doing. Jonathan took off the earphones. "It's really cool," he said. "Harlan showed me how to connect with all the monitoring equipment topside. There are cameras hidden in fake cacti which can be directed with this joystick. There's also listening devices and motion sensors. Want to try it?"

Pitt declined. Instead he told the others that Cassy had described to him some astounding and disturbing things about the aliens.

"Like what?" Sheila asked while continuing to work.

"The worst thing," Pitt said, "is that they have the infected people building a huge futuristic machine they call a Gateway."

"And what's this Gateway supposed to do?" Sheila asked, while gently swirling a tissue culture flask.

"It's some kind of transporter," Pitt said. "She was told that it will bring all sorts of alien creatures to Earth from distant planets."

"Jesus H. Christ!" Sheila exclaimed. She put down the flask. "We can't face any more adversaries. Maybe we'd better just give up."

"When is this Gateway going to be operational?" Harlan asked.

"I asked the same question," Pitt said. "Cassy didn't know, but she had the impression it was imminent. Beau told her it was almost finished. Cassy said there were thousands of people working on it."

Sheila exhaled noisily in exasperation. "What other charming news did she tell you?"

"Some interesting facts," Pitt said. "For instance, the alien virus first came to earth three billion years ago. That's when it inserted its DNA into the evolving life.''

Sheila's eyes narrowed. "Three billion years ago?" she questioned.

Pitt nodded. "That's what Beau told her. He also told her that the aliens have sent the enabling protein every hundred million Earth years or so to 'awaken' the virus to see what kind of life has evolved here and whether it was worth inhabiting. What he meant by Earth years she didn't ask."

"Maybe that relates to their ability to go from one universe to another," Harlan said. "Here in ours we are caught in a space/time freeze. But from the point of view of another universe, what's a billion years here, might only be ten years there. Everything's relative."

Harlan's explanation brought on a moment of silence. Pitt shrugged. "Well, I can't say it makes much sense to me," he said.

"It's like a fifth dimension," Harlan said.

"Whatever," Pitt said. "But getting back to what Cassy was telling me, apparently this alien virus is responsible for the mass extinctions the Earth has witnessed. Every time they came back here, the creatures they infested weren't suitable, so they left."

"And all the creatures they'd infected died?" Sheila asked.

"That's how I understand it," Pitt said. "The virus must have made some lethal change in the DNA causing the disappearance of entire species. That created an opportunity for new creatures to evolve. She told me that Beau had specifically mentioned this with regard to the dinosaurs.''

"Well, I'll be," Harlan said. "So much for the asteroid or comet theory."

"How did the creatures die?" Sheila asked. "I mean, what was the specific cause of death?"

"I don't think she knew that," Pitt said. "At least she didn't tell me. But I can ask her later."

"It might be important," Sheila said. She stared off into the middle distance with unseeing eyes. Her mind was churning. "And the virus supposedly came to Earth three billion Earth years ago?"

"That's what she said."

"What are you thinking?" Harlan asked.

"Is there any anaerobic bacteria available in the lab?" Sheila asked.

"Yeah, sure," Harlan said.

"Let's get some and infect it with the enabling protein," Sheila said with mounting excitement.

"Okay," Harlan said agreeably. He stood up. "But what's on your mind? Why do you want bacteria that grows without oxygen?''

"Humor me," Sheila said. "Just get it while I prepare some more enabling protein."