“The theory doesn’t always work,” said Laz. “You had Afrasia versus America as your main example. But what about Australia? It was just as isolated for a long time, because no matter how low the ocean level got, there was no land connection between Asia and Australia.”

  “And Australia remained a barren wasteland,” said Mumbo.

  “No it didn’t,” said Ivy. “Australians found ways to supply water year-round, and they carefully protected and reseeded their most important crops on the lands where they grew naturally. No other humans have been so perfectly adapted to their environment, maintaining a surprisingly large population on some of the most arid, barren lands on Earth.”

  “Farming?” asked Laz.

  “As far as I can tell,” said Ivy, “Australians invented agriculture thirty thousand years before it cropped up in the Middle East.”

  “ ‘Cropped’ up,” said Laz. “I saw what you did there.”

  “Nobody else ever created such perfect ecological balance. The Australians were healthy and prosperous—and for a long time, they were exempt from worldwide plagues, just like the Americans were.”

  “So, three different worlds,” said Mumbo, “and they all developed ideas and practices that profited the other worlds, when they finally met.”

  “Except Europeans brought sheep to Australia,” said Ivy, “and destroyed the entire civilized structure.”

  “And European diseases,” said Laz, “decimated the native population of the Americas.”

  “The worst plagues always started in one place and arrived suddenly in another,” said Mumbo. “And if, after a thousand or ten thousand years of completely separate development, when people no longer believe those old myths about Portals to other worlds—or to heaven, or to hell, however the myths develop—when somebody like you is born, and they side step and open Portals, then we have the developments on eight or nine or ten separate worlds. It’ll be a tough transition, adapting to each other and coping with diseases and asymmetric technologies, but the worlds will really have been independent, developing however they develop.”

  “Sounds like you got it all thought out,” said Ivy.

  “All my life,” said Mumbo. “Deciding on my life’s work.”

  “All thought out,” said Ivy. “And stupid through and through.”

  Mumbo looked genuinely crestfallen. So all that self-confidence was just for show, apparently. He wanted them to understand and approve of his plan.

  “She made it sound a little harsh,” said Laz, “but why didn’t you already see the flaw in this?”

  “Maybe because there isn’t one?” said Mumbo.

  “We’ve had a lot of experience seeing how changing one or two things can transform the future,” said Laz. “We’ve changed the world, at least locally, many times. We’ve lost friends and changed careers, and we remember all the timestreams we eliminated. And here’s what we’ve learned. Nothing works out the way you thought it would. Your plan, Chrysanthemum, is only worth doing if it benefits the human race. And for all we know, it will be disastrous.”

  Mumbo swung his legs under the sheet and cuddled the sheet up under his neck. “You guys think you’re so smart.”

  “We’ve experienced things that you haven’t,” said Ivy.

  “Don’t explain it away,” said Laz. “He should have figured it out. Nothing ever works according to plan.”

  “Everything works according to your plans,” said Mumbo, “because you keep side stepping until it all goes your way.”

  “Most of the time, we don’t even have a ‘way,’ ” said Laz. “We side step in order to avoid something. And as long as the thing we’re avoiding doesn’t happen, then our plan worked.”

  “But you’re looking for positive outcomes, Mum,” said Ivy.

  “Not any particular outcome,” said Mumbo.

  “You have the idea in your head,” said Laz, “that in isolation people, nations, whatever, will come up with good things that nobody else ever thought of, and when it finally does have a chance to spread to other timestreams, it’ll be a blessing. But it could be a disaster, like it was to Australia. To the American first nations. To the kingdoms of Africa.”

  “History is in the past,” said Mumbo. “I’m working on the future.”

  “Everything in the past,” said Ivy, “used to be the future.”

  “Which nobody can foresee,” said Mumbo. “So you don’t know if things will go down the toilet.”

  “A lot of things go down the toilet all the time,” said Ivy. “All of history is just one big flush.”

  “Look, Chrysanthemum,” said Laz. “We don’t know that you’re wrong. Maybe if you separate all the worlds, it’ll benefit humanity ten thousand years from now.”

  “But that’s only if other side steppers come along,” said Ivy.

  “No,” said Mumbo. “Because there’s another benefit. Suppose the worlds never come together. Each one just has its own future and that’s that. But no matter what, humanity is going to survive. One group or another will still be thriving ten thousand years, a hundred thousand years from now. Some of them will put colonies in space, mine the asteroids, travel to other solar systems. Some will maybe bomb each other back to the Stone Age. More than once.”

  “But we’ll survive,” said Ivy.

  “We’ll have a dozen chances to survive. Or eight, or whatever,” said Laz. “That’s legitimate. That makes sense.”

  “I can’t believe you’re saying that,” said Mumbo.

  “Well, if you want, I can side step into a timestream where I didn’t say anything like that.”

  “No, this’ll do,” said Mumbo.

  “Insurance through duplication,” said Ivy. “Odds are that they won’t all fail.”

  “Mumbo,” said Laz, “your purpose may be noble, your plan might be better than Ron’s, but the Tesserans slaughtered a school full of children.”

  “Not what I planned,” said Mumbo.

  “But that’s the problem,” said Laz. “It’ll never turn out how you planned. People don’t do what they say they’ll do. People can’t be trusted except the few times that they can. And no matter how bad you think people are, they’ll surprise you by being far, far worse.”

  “You’re such an optimist,” said Ivy, in mock admiration.

  “Did you bother trying to find out how the Tesserans usually make war?”

  “They had regular weapons, they talked about fighting armies,” said Mumbo.

  “So they didn’t discuss their future atrocities in front of you?” asked Ivy.

  Mumbo looked embarrassed. “It never crossed my mind that they might do that.”

  “Well,” said Laz, “don’t worry. Nobody can call you to account if they can’t see you.”

  “I don’t want to live the rest of my life invisible,” said Mumbo.

  Laz and Ivy looked at each other. “But at least you get to live the rest of your life,” said Ivy.

  “I’m not at war with you,” said Mumbo.

  “And we’re not at war with you,” said Laz. “What good would it do us? You’re untouchable and unfindable, if you feel like it.”

  “I still think we can work together.”

  Ivy shook her head. “We’re working with Ron. Trying to help him give the timestreams a peaceful, productive start.”

  “That’s what he says,” said Mumbo.

  “He tends to do what he says he’ll do,” said Ivy.

  “As do we,” said Laz.

  “So you’re going to keep your word to Ron instead of helping me.”

  “Chrysanthemum,” said Laz, “there’s one way we can help you, and we’ll do it.”

  “And what’s that?” asked Mumbo.

  “I’d also like to know,” said Ivy.

  “Since we can’t stop you from doing what you want to do, we won’t try to stop you.”

  “How is that helping me?” said Mumbo.

  “Because we can actually make more trouble than you might guess,” said Laz.

  Ivy led the way toward the door. As she did, Laz told Mumbo, “Find a way to get your naked ass out of this room.”

  At the door, Ivy stopped. “Mum, is Nasty with you in this?”

  “We’re together in everything,” said Mumbo.

  “So you haven’t explained anything to her,” said Ivy.

  “I said we’re—”

  “Mum,” said Ivy, “you gave me an evasive answer.”

  “I always do that.”

  “I have no doubt of it,” said Ivy. “But you haven’t told Nasty anything.”

  Mumbo stared fixedly at nothing.

  “Nuff said,” Ivy replied. She pulled on sweats and a long-sleeved tee. Laz hated the way that even though Mumbo didn’t move his head, his eyes moved to focus on Ivy dressing.

  “Show’s over,” Ivy said when she got her shoes on and stood up. So she had been aware of Mumbo’s gaze.

  Ivy walked past Laz, through the living room, and out into a light rain.

  Mumbo answered, “It isn’t always easy to tell people what you—”

  “You know Nasty will hate your plan,” said Laz. “But she’ll also know that once you decide, there’s no stopping you.”

  Laz didn’t wait for a reply. Mumbo’s silence was eloquent. Laz was out the door in a moment, caught up with Ivy, and they held hands on the way to Ron’s building. They would have to go over everything Mumbo had said and what they thought it meant. If he was lying, what was the truth he was trying to conceal? If he wasn’t lying, what advantage did he expect to gain by letting accurate information through?

  Halfway to Ron’s building, though, Laz realized that there was something more important. “It’s not all right, what he did,” Laz said. “What he kept doing.”

  “I know,” said Ivy.

  “I don’t want you to have to live in fear. Without privacy, without safety.”

  Ivy sighed. “But there’s nothing we can do about it now.”

  “There is something we can do, something very important.”

  Ivy stopped walking and faced him. “I don’t want you to punish him.”

  “I don’t know how I’d do it if I wanted to.”

  “So you don’t want to punish him?” Her eyes were trying to express her normal merriment when she was being sarcastic, but he knew what she was really asking.

  “Ivy, when I came in and saw him there, and you standing up so angry—I’ve never seen you so angry, I didn’t know you could be so angry—”

  “I was terrified and humiliated,” said Ivy. “He touched me.”

  Laz stood there, quite certain that she would hate it if he asked her where Mumbo had touched her, but also knowing that he didn’t know how much to hate and fear Mumbo until he knew where or whether he drew the line in his abusive contact with Ivy.

  “I’m a grownup, Laz,” Ivy said. “I can deal with it.”

  “On the contrary, Ivy. You can’t deal with it alone because we’re a team. We’re partners.”

  “We’re engaged, as I recall,” said Ivy.

  “We work as a team, and we live as fiancés,” said Laz.

  “He touched me on my side, my bare waist, between shorts and top. Not any particularly intimate place, but it was bare skin and that made it intimate, and I hadn’t known he was there, which made it all the more shocking. And then I realized he was naked when he did it, which made it all the more frightening.”

  “I bet that in his pathetic spoiled immature mind, it was just a funny prank,” said Laz. “Stop, don’t yell at me. Just because it was a prank in his mind doesn’t mean that it actually was a ‘mere’ prank. It was, in fact, an assault, a crime with some pretty steep penalties in Central Time City. And the fact that he was naked makes it a sexual assault, which pushes the penalties even higher.”

  “If we try to take legal action, he’ll only disappear.”

  “You’re right,” said Laz.

  “So what’s the point of this discussion?” asked Ivy.

  “I would say that there’s a high likelihood of his doing something equally outrageous in the future, and probably more so.”

  “Which we can’t prevent, since he can walk through walls.”

  “I think you need to talk to Nasty and tell her what happened. Find out if his maneuver meant anything. If he has a violent streak. We have to know.”

  “Sure,” said Ivy.

  “And you also need to tell Nasty to talk to her brother and tell him that if he ever touches you again, or shows up inappropriately dressed—”

  “Undressed—”

  “It will be the last thing he does as a living organism on this Earth.”

  Ivy closed her eyes and shook her head. “You’re not a killer, Laz. And even if you were, he can’t be killed.”

  “That’s what he wants us to believe,” said Laz.

  “And I believe it,” said Ivy.

  “But I think I already know how to punish him sharply if he does anything like that again.”

  “Which he probably won’t do,” said Ivy.

  “Probably won’t, which means certainly will do something similar. Testing another boundary.”

  “But he’ll choose a time when you aren’t there to do it.”

  “If he’s smart, yes, he will. But what he doesn’t understand, what you don’t yet understand, is that he already crossed the line. He already committed a crime against my beloved.”

  “Surprisingly, it never sounds stupid when you call me that. I think because I believe that you mean it.”

  Laz was glad to know she felt that way. “Ivy, I’m going to exact a punishment from him for what he already did. Just making threats won’t deter him at all, since he doesn’t believe that anybody can touch him.”

  “Because nobody can touch him.”

  “Al contrario, mi preciosa,” said Laz.

  “I love it when you speak Latin.”

  “Spanish,” said Laz.

  “I speak Spanish, and that wasn’t Spanish.”

  “I don’t know how to say ‘sister’ in French, so I didn’t know how to adapt ‘Au contraire, mon frère,’ into ‘On the contrary, my sister.’ ”

  “Ma sœur,’ ” said Ivy.

  “Okay, I actually knew that, I just don’t know how to pronounce it like that.”

  “I just showed you how.”

  “I don’t know how your mouth produced that perverse conglomeration of vowels. The French obviously don’t want anybody else to speak their language.”

  “Ma sœur,” she repeated. “Practice and you’ll pick it up.”

  “Mi preciosa,” said Laz. “Meu amor. L’espoir de ma vie.”

  “So we’re back to French.”

  “Ivy, in the very near future, at a time when he thinks all is well between us, when he expects nothing because he assumes I would not launch an unfair attack, I will attack him. Hard.”

  “Please don’t,” said Ivy.

  “I will not use any weapon,” said Laz.

  “If you try, it won’t work, but then he can attack you in return, and you’ll have no defense.”

  “Ivy, I have heard your objections and your warnings, and I am this close to obeying you. But in a life where he’s never known violence against himself, Mumbo has become overconfident. I’m going to bop him on the nose. I think the psychological effect on him will be very much like a flamethrower in his face and a cancer-causing bullet in his liver.”

  “That’s a lot to get out of one punch in the nose.”

  “It will be a very eloquent punch.”

  “Please don’t do it,” said Ivy. “Why provoke him?”

  “He doesn’t need provocation. He needs swift and sure retribution.”

  “With you as judge and jury.”

  “I witnessed his offenses,” said Laz. “So did you. Why would we need a trial?”

  “This is a dangerous game,” said Ivy. “Our gifts are remedial—we can use them to fix things. But when you needed a weapon against the dogs, you had to practice rock-throwing.”

  “I’m not going to throw a rock at him,” said Laz.

  “Our gifts can’t match his for military usefulness,” said Ivy, “so don’t set out on a road we’re not equipped to finish.”

  “I’m equipped,” said Laz.

  “Laz, he’s a spoiled little monster.”

  “Which is why it’ll be good for him to find out that vile actions have unpleasant consequences.”

  “The consequence of his being an asshole is that he’ll die alone,” said Ivy. “And live alone.”

  “By the time he really understands that consequence, he’ll be dead.”

  “My honor is already saved. You saved my honor when you came into my room—”

  “My coming in and seeing you in your underwear is yet another crime that he is charged with,” said Laz.

  “It doesn’t matter,” said Ivy. “After all, you already saw me completely naked.”

  Laz found himself growing angry. He controlled himself and said nothing.

  “I’m sorry,” Ivy said. “I promised never to mention that again.”

  “You know, my love,” said Laz, “it was Zero-Laz who saw your incomparable form inside a box, through a plastic lid, and he side stepped away the moment he saw that you were underdressed. He side stepped to a timestream in which you wore pajamas in the box.”

  “If you remember it, you did it,” said Ivy.

  “Then wasn’t I gallant?”

  “Oh, my noble knight, none gallanter than thou. But I have already promised to wed thee, so there will be no more secrets.”

  Laz shook his head. “All joking aside, Ivy, he took liberties that only a husband should take, and then only by consent.”

  “And I’m begging you not to get into some physical altercation with a dork who can vanish into thin air.”

  “I’m glad to know you care about me so much, but sad that you trust me so little.”

  “I trust you implicitly,” said Ivy. “To do the right thing.”

  “But you don’t trust me to decide what the right thing is.”

  “And you don’t trust me to decide what the right thing is.”

  “So let’s both do the right thing,” said Laz, “as we define it.”

  “Don’t come complaining to me if you get killed,” said Ivy.