“Did you feel that?” Gilly asked. Samson sat up calmly and reached for his ice axe. “No. I didn’t feel anything.” The couple was at nearly 9,000 feet resting on the edge of the glacier that corkscrewed precipitously to the top of Guth Peak, elevation 10,627. It was mid-morning, the early September sun bright and dangerous. “Now, I’m very concerned about this next part,” Sampson said as he motioned towards the glacier. “You can’t think about this like snow, Gilly. We’re about to cross a river. A very solid-looking river, but a thing in motion nonetheless. There are eddies and currents and deep pools—many of them disguised or hidden. That’s our focus, not these inflaton fields you keep warning me about.” Gilly tipped up her sunglasses and squinted at the blinding expanse of snow and ice. “Maybe this isn’t such a good idea. Maybe I’m not ready for this.” Checking his crampons first, Sampson stood up. He surveyed the route to the top and then his girlfriend—and lab partner—who’d begged him to take her on this climb. She was fit and in shape. She could do it, but she had the jitters. Sampson didn’t take that lightly. “Let’s go down, then,” he suggested. She grimaced. “Too easy. Give me another minute. Tell me how we’re going to do this.” “Hey, we’re not going to do something you’re not ready for,” Sampson reminded her. “I’ve climbed this peak three times and this is the toughest part, crossing this exposed face. Every footstep is potentially dangerous. That’s why we’re roped. If one of us goes into a crevasse or starts to slide, the other has to act fast and become an anchor. You remember how to do that?” Gilly nodded. They’d practiced it ad nauseum on shorter, easier climbs in preparation for today. “Good,” Sampson continued. “Once we get across the face, then it’s just a breathless hoof up, and the hope that nothing really large overhead breaks off and hits us.” He knocked on his climbing helmet. “Just like in the lab, we try to minimize risks. We plan. We prepare. Then we go climb the mountain because it’s there—and you never know what you’ll see at the top.” He smiled and Gilly remembered why she was here. That smile. Sampson Becker wasn’t all that memorable as a doctoral physics lab partner, but when he talked about climbing, he glowed like the Milky Way. Like she was staring into immense and mysterious power. Gilly Keppler had wanted to experience that power first hand. Her work at the linear accelerator lab wasn’t enough anymore. It had opened the doors to mind-bending wonders of inflationary cosmology and the hidden realities of bubble universes. When she had first been wrestling with the concept of cascading realities, Sampson had used the analogy of Edmund Hillary and Tenzing Norgay standing atop Everest. Their potential energy, should it be tipped by a small quake or gust of wind, could send them hurtling five hard miles down. The potential energy released in such a calamitous fall would engender a slew of realities. Inflaton fields such as these existed everywhere waiting for a quantum jitter to form one or more pocket universes. Gilly had wanted to stand atop a mountain and feel that potential energy. And, yet, a dozen times during their ascent this morning she had felt a tremor, a jitter, rushing up her spine and spreading out along her shoulders and arms. Each jolt had left her tingling with trepidation. When she told Sampson about the sensation, he’d merely chalked it up to nerves. She was sure it was nerves, though there was more. Her vision had begun to waver. As Sampson started to probe the path ahead of them, she began to see two of him. Two Sampsons, poking at the snow with his ice axe. One finding the safe path, the other plunging down the steep mountainside. A strange double vision, a splitting probability wave. Gilly knew she was sliding to the edge of what was real. And here she was on a literal edge. She wondered if she was suffering from altitude sickness. Was she oxygen deprived? She took a deep breath and let it out slowly. Thinking about Sampson’s cobalt blue eyes could leave her breathless. A strange sensation ran up her spine. She shivered and dug her fingers into the snow trying to steady her nerves. “Remember, Professor Joiner’s lecture on the Inflationary Multiverse?” she asked suddenly. “Do you believe that stuff?” Sampson stared back at her. “Stuff? We’re physicists. You want to be more specific?” “Inflaton fields with enough potential energy, so that even a quantum nudge can bring a whole universe into being—birth a new reality.” Sampson sighed. “Gilly, if we’re going to get into quantum jitters, I think we’re done for the day. You gotta focus on this reality if we’re going to make it safely to the top.” “But don’t you wonder, if every step we take shakes a new reality into being, wouldn’t we feel it? Wouldn’t it somehow register?” Sampson’s laugh boomed out over the glacier. “Not here. Mother Nature won’t suffer that kind of competition on a day like this.” He offered Gilly his hand. “Let’s go down. You’ve done amazing for a first ascent.” Gilly felt an unexpected tingling in her neck that flowed down her shoulders to her fingertips. She squeezed Sampson’s hand firmly. “Let’s finish this.” He eyed her carefully. “You sure? No jitters?” “Plenty, but they’re not small enough yet.” “Small enough?” “Yup.” Sampson considered the enigma that was his girlfriend for a moment, then he went into mountain guide mode. He checked her gear and his, then their ropes and, once more, went through the plan before they stepped out onto the glacier. Gilly, still tingling, followed. They made the summit in an hour and a half. After taking a few pictures of the magnificent view, Gilly went to Sampson who was carving their names in the ancient snow with his ice axe. She put her arm around his waist. He pulled her close. A universe jittered. Theirs, too.