“Remind me of your name, dear,” Dr. Moss said. “I’m afraid I’ve forgotten it.” He tapped himself on the temple. “Mind like Swiss cheese, and growing holier by the day!”
“Sasha,” I told him, gathering my confidence. It seemed like forever since I’d said my own name out loud. “Sasha Lawson.”
“That’s right. Ms. Lawson.” Dr. Moss grinned at me. “I can’t tell you how happy it makes me to find you got through the tandem in one piece.” I didn’t doubt it; he’d invented the anchor that had brought me to Aurora, so if I hadn’t survived the journey, it would’ve been at least partially his fault. I shot Thomas a dubious look. This was the man who was supposed to help me? He seemed a little nuts.
“Was that Chuck Berry you were playing?” I asked.
Dr. Moss snapped his fingers, impressed. “Right you are. I was introduced to the Father of Rock and Roll by another one of your kind many years ago, and I’ve never lost the taste.”
Dr. Moss sat down on a nearby stool and drummed his fingertips on his knee. The steel tabletop was littered with notebooks containing lines of cramped, handwritten notes. Seeing them—the whole place, in fact—reminded me of Granddad’s lab at the university, except larger and shinier. On the table there stood a large glass bottle of the type that might once have contained vodka, and it was filled with tiny origami stars in a rainbow of colors. In fact, they were scattered all about, piling up in the empty spaces and peeking out from beneath his notes.
I picked up a green one and held it between my thumb and forefinger. I wondered if the one I’d found in Juliana’s nightstand had its origin here, in Dr. Moss’s lab. “Did you make these?”
“Actually,” Thomas said, taking it and dropping it into the bottle, “they’re mine.”
“Yours?” Then had Thomas given Juliana the blue star, as some sort of token or memento? Was that why she’d kept it? Was that why she’d hidden it away?
He nodded. “When I was little, I was anxious and fidgety. One of my teachers taught me how to make these, and told me that whenever I felt antsy, I should just take out a piece of paper, rip it up, and make stars.” He gave me a wry smile. “The habit stuck.”
I smiled at the mental image of a boyish Thomas sitting at a classroom desk, making stars with his restless hands. “Aw, that’s sweet.”
He rolled his eyes; apparently, “sweet” was not a compliment to a soldier. He ran his fingers through his hair and dipped his head to hide a faint pinkness that colored the tips of his ears. “Anyway,” he said. “I spent a lot of time down here with Mossie during the planning stages of Operation Starling, which is, you know, why they’re here.”
“I’ve been keeping them safe for you, boy,” Dr. Moss said, not even bothering to look up from a nearby text that had drawn his attention away from us.
“What’s Operation Starling?” I asked. Dr. Moss swiveled around and Thomas lifted his eyes to mine. A moment of silence passed. “Oh,” I said, my voice flat with realization. “Right. Why do you call it that?”
“It’s, um … kind of a joke,” Thomas said, with a soft snort of self-effacing laughter.
“Oh really? What’s so funny about it?”
“Not funny,” he said. “It’s just that Juliana’s KES code name is ‘Sparrow.’ Sparrows and starlings are related, I guess.”
“They’re from the same biological order,” Dr. Moss explained. “Passeriformes.”
“Fascinating.”
“It was his idea,” Thomas said, pointing at Dr. Moss. “As you can probably imagine.”
“Well, children, I haven’t got all day,” Dr. Moss said. “And I assume it wasn’t an interest in ornithology that brought you here, so why don’t you tell me what did, eh?”
Thomas drew in a deep breath. “We have a situation.”
“Oh? What sort of situation?”
“Go ahead,” Thomas said, putting a hand on the small of my back and pushing me forward. “Tell Mossie what you told me.”
I still wasn’t quite sure about Dr. Moss, but I didn’t see that I had a better option, so I explained everything as best I could. This time, it came out easier, and more intelligibly. As he listened to me describe my “situation,” excitement bloomed across Dr. Moss’s face.
“Well,” he said when I was finished, with soft but potent enthusiasm. “That is interesting.”
Just interesting? “Have you heard of that happening to other people?”
“Other people?” He tapped his chin with his fingers. “Not as such.” The wheels of Dr. Moss’s mind were turning swiftly and energetically, fueled by a new mystery, and his eyes held that same glint of excitement Granddad used to get when he was on the verge of a particularly gratifying discovery in his own work. “What do you know about parallel universes, Ms. … ?”
“Lawson,” Thomas and I provided in unison.
“Right.” His hands flapped in the air, an impatient gesture meant to spur me to answer.
“Not a lot,” I admitted. “My grandfather is a physicist, but it’s not something I was personally very interested in—up till now, anyway.”
“Hmmm.” My lack of knowledge disappointed Dr. Moss, but he soldiered on with an air of great burden. “Then I guess I’ll have to start with the basics, won’t I?”
“That would probably be best,” I said.
Dr. Moss nodded, rushing to a keyboard and typing a series of quick commands. There was a large screen on the opposite end of the laboratory that took up almost the entire wall. When Dr. Moss was finished, the screen, previously blank, held one inscrutable image.
I know that symbol, I thought with a sudden, grave certainty. I struggled to remember where I had last seen it, but I couldn’t. Was it something Granddad had once shown me? Then I realized—it was the Libertas insignia, except that instead of stars it was made up of dots.
“What’s that?” I asked, advancing toward the screen.
“No touching the equipment, if you please,” Dr. Moss scolded. I drew my hand away.
“That is a tetractys,” Dr. Moss told me. “A mathematical symbol dating back to about 500 BC. But the shape doesn’t matter—it’s what the tetractys represents that’s important.”
“And what’s that?” I asked, squinting so that I could read the type.
“Universes.” I could hear a grin in his voice when he said the word. If nothing else, Dr. Moss certainly had a flare for the dramatic.
“As we are all well aware, there is a large number—perhaps infinite number—of universes in existence,” Dr. Moss continued. “But what you may not know is that there are many different kinds of universes. What you see on the screen is a method I’ve developed for categorizing universes in their many forms.” Dr. Moss took one look at my baffled expression and said, “Allow me to explain further.”
“Please do,” I urged.
“For the purposes of this demonstration, let us consider Earth to be our home universe,” Dr. Moss said with a nod in my direction. “At the top of the pyramid, you have Earth, and all of the universes that are separated from it by what I’ve taken to calling zero degrees. These are universes that are virtually indistinguishable from Earth itself. They are nearly identical, apart from minuscule changes that have no global consequences. For instance, Thomas is wearing a blue tie today. In a zero-degree universe, he’s wearing a black tie. A small difference with no measurable impact.
“The second row is representative of all universes that are separated from Earth by one degree. These are distinguishable from Earth, but are not so different that the world appears substantially changed. For instance, if you were comparing Earth to another world with one degree of separation, at any given time the President of the United States could be a different person in each world, but there would still be a President of the United States. Do you understand?”