Sedna and Kore soon called it a night. Kore gave Dema an extra tight hug before she went. "I don't know how you can talk so calmly about being ephemeralized by Count Dracula himself. But you seem solid enough now." 

After a final squeeze she followed Sedna up to bed. Cern and Dema were about ready to go too, but Naga would not be denied. She wanted to know more about Gaia. 

"There are modern theories that go by the name of Gaia," she said, "Theories of how life arose in the deep hot biosphere, thriving on the energy that flows upward from the core, before it learned to tap the energy that flows downward from the sun."

It was Cern's turn to reply. "I knew of some of those ideas, and our experience bears them out. Biogenesis, the evolution of life forms, is all about symbiosis, the emergence of more and more complex relationships."

"Symbiosis, because only if an emergent form helps other forms survive does it have long term survival value itself."

Cern nodded. "The possible becomes probable, the probable becomes real, and the reality of life becomes more and more robust."

"That's the lesson Vlad refused to learn," Dema added. "He could not see beyond his own self-aggrandizement. He was always a parasite, never a symbiote."

"But don't all symbiotes start as parasites?"

"Parasites or predators. That's why Gaia takes the long view. It is never certain what will happen. A pure parasite may destroy its whole community, itself included. A predator often mostly culls a herd of its weakest members, leaving it stronger, but sometimes goes too far, to its own detriment."

"And what is Gaia's role?"

"She is passive. She does not favor any single form. She only provides the background will to contrive order out of chaos, to survive in ever more creative ways."

"Those who personify some aspect of that will are favored overall," said Dema, "But passively, as Cern said. She does not directly interfere."

"What about on a planetary scale? Climatic stability and all that?"

"I don't know. My link to Gaia felt—feels—profound, but on that scale it remains occluded." 

"Mine too," said Cern, "But it is hard to account for the long term stability of our global environment, billions of years with an average temperature variation of less than fifteen degrees in spite of the sun itself getting hotter, without thinking that Gaia has something to do with it."

Naga'a eyes were alight. "Suns evolve too. There is pretty good evidence that when early generations of suns collapse and explode, the waves of energy they give off compress the clouds of gas around them in such a way that they develop into new suns. Without this cycle whole galaxies would die off, but instead they continue, producing generation after generation of stars until they number in the billions."

"Just like people."

"It's hard not to think of a galactic version of Gaia."

"I almost feel I could go there..."

Naga continued. "And beyond that, there is at least one theory that speculates on black holes being the seeds of other universes, that universes evolve on the same principles, the most successful universe producing the most black holes."

"And to produce the most black holes it must produce the most stars?"

A nod. "And to produce the most new stars the stars must produce the most carbon and other elements, because that is what it takes to seed new stars."

"And that also seeds planets with the stuff of physical life..."

"So instead of being highly improbable, a world like ours—a universe like ours—becomes highly probable."

"A universal Gaia."

"Or even a Gaia of the multiverse."

"Feynman thought he was joking when he said. 'If you don't like it, go somewhere else.'"

"Except that you can't go somewhere else if the only way to get there is through a black hole, because that destroys everything."

"Everything physical..."

"But as we well know, everything is not physical..."

"I wonder what they are like, those other universes..."

"The highest probability is that most of them are a lot like ours."

"On the whole. But very different in detail."

"Of course. Like every fantasy story you ever read. Every fantasy story you can imagine."

"But back up a bit. If instead of being highly improbable, our world is highly probable, and even in this universe there are billions of galaxies, billions of stars, billions of planets..."

"Right. Maybe Feyman really wasn't joking. There are lots of 'somewhere elses' right in our own galactic neighborhood."

"So maybe we could go there. Physically. Like Star Trek."

Dema yawned. "I've got my hands full right here, thank you very much, what with the likes of Vlad."

Even Naga's eyelids were beginning to droop. She stood up. "Me too. Time to call it a night. Enough speculation about parallel universes."

Parallel universes. That set off another line of thought for Cern, something about the parallel universes of people. He looked at Dema, who looked back sleepily and leaned against him. His only thought then was of awe that their parallel universes had merged so completely.