“Of course you don’t,” Nancy said softly. “That’s why I’m here. I’ve come to explain.”

  “OK,” I said. “Look, can Izzy join us? She’s here, too. She came for moral support.”

  “Of course she can.” Nancy looked around us.

  “She’s, um, she’s behind that tree over there,” I said, waving Izzy over.

  “OK, ready,” I said as Izzy joined us and I shifted along the bench to make room for her.

  “Sure?” Nancy asked, giving Izzy a quick smile.

  We both nodded.

  Nancy took a breath. “OK. So, some years ago, when I’d just started working as a midwife, one of the doctors at the hospital told me he was starting a research project.”

  Research. The word made my insides flutter. Research, as in a lab full of books and test tubes and computers and supersonic doors and bright lights and high-tech equipment for experimenting on people like me? I kept quiet and waited for Nancy to continue.

  “He’d won a grant from a new government department and asked me to join him. He was trying to find a cure for . . .” Nancy cleared her throat. “Well, for all sorts of illnesses that there was no cure for. Only, it didn’t work. Then, when the funding got cut, James gave up. On everything.”

  “James?”

  “Dr. Malone. My colleague. For a long time, we didn’t even talk about it.” Nancy twirled a thick dreadlock around her fingers. “Just a couple of months ago, he approached me about starting up our research again.” She turned to look at us both. Her eyes seemed to have an extra sparkle in them. “James is one of the best doctors I knew. He’s done things others wouldn’t even attempt; he sees links that everyone else misses. The man is a genius. If he wanted to give it another try, I was in.”

  “What made him think it would work now if it hadn’t worked then?” I asked.

  “He didn’t know if it would or not, but he wanted to try. It was exactly ten years since . . . well, since everything had fallen apart. Plus, he’d come into some money, which meant he could restart the project without government support. He rented an office space, turned it into a lab, and we started working to catch up with where we’d left off.” Nancy paused.

  “And?” Izzy prompted.

  “And it was hard. When we’d abandoned the project a decade ago, James destroyed virtually everything to do with it. That meant we were starting from scratch. But then we had a breakthrough.”

  Nancy hesitated and glanced at me. “It was around your birthday,” she went on. “I’d been shopping for a present for you. I saw something nice in a shop in town.”

  “Tiger’s Eye?”

  Nancy nodded. “There were a few things that I liked. The necklace I gave you and a couple of bracelets. One with an amethyst in it, the other with a moonstone. I couldn’t decide which to get, so I bought all three and decided I’d give you one and keep the other two myself.”

  “Did you know there was anything . . . special about the crystals?” I asked, suddenly realizing it was possible that Nancy still didn’t know what the crystals did. Possible, but unlikely.

  “No,” she replied. “It was a couple of days after your birthday that everything changed. I’d left the two bracelets in the lab. James was on one side of the room, using the centrifuge in an experiment to separate isotopes so we could analyze the components of our serum.”

  I stared blankly at Nancy, wondering why she’d suddenly started talking in a foreign language.

  Nancy noticed my face. “Basically, he was working on a controlled experiment with lots of delicate items. Meanwhile, I was rushing around doing too many things at once and not concentrating properly on any of them.”

  “Sounds like an accident waiting to happen,” Izzy mused.

  “Exactly. James was at a crucial moment. He’d assessed the sedimentation principle with all the different variables, and — ”

  Nancy stopped as she looked from me to Izzy. “OK, basically, James had poured the serum into a special kind of bowl, and at that exact moment, I swung around, grabbed my hospital bag from a shelf, and knocked the amethyst bracelet into that bowl.”

  “Yikes!” I exclaimed.

  “Yes. James had spent hours getting to this point in his experiment and he wasn’t happy, but then something incredible happened. The bowl began to vibrate — ever so gently — and the serum inside it frothed and fizzed.”

  I felt the hairs on my arm tingle as Nancy talked.

  “And then, the strangest thing of all,” she continued, “the bracelet itself came right out of the bowl and hovered above it for a few seconds. A moment later, it fell back down, the serum stopped fizzing, and it was as though nothing had happened.”

  “Wow!” Izzy blinked at Nancy. “What did you do?”

  “To begin with, we stared at the space above the bowl, not speaking. I think we were both afraid to be the first one to say what we’d just seen in case the other one told us we were crazy.”

  Yup, I knew all about that one.

  “Once we’d recovered from the shock, we fished out the bracelet and put the other one in the serum. The bowl shook and the serum fizzed again. But this time, when we took the crystal out, it was ice-cold. We didn’t know what any of this meant, but we knew that something big was going on.”

  I suddenly fit a piece of the jigsaw puzzle into place. “And then you took the doctor back to Tiger’s Eye, where he bought as many crystals as possible so you could try them all with the serum and see what happened!”

  “That’s right. He was so excited. It was as if he had a new lease on life. I hadn’t seen him like this since . . . well, I hadn’t seen him like this for a very long time.”

  I nibbled on my thumbnail. “Did he buy a rose quartz?”

  “It was the first one we tried. I kept thinking about you and the birthday present I’d given you a week earlier. At that point, I had no real reason to think it would have done anything but, even so, I wanted to find out what it could do.”

  “And? What happened when you put that one in the liquid?” I prompted.

  Nancy met my eyes. “It turned invisible.”

  I held her gaze. Could she tell? Did she know that I could turn invisible, too? Should I ask? Eventually, I said in a quiet voice, “It did the same to me.”

  Nancy nodded and released a breath that came out in a low whistle. “What happened?” she asked. “How did you find out?”

  I filled her in on what had been going on. How the crystal didn’t work on Izzy but it worked on me. How I had to clear my mind for it to take effect.

  “That’s interesting,” Nancy mused when I told her this. “It must have something to do with the clarity of the crystal mixing with the purity of the serum.”

  OK, whatever.

  “So, why me?” I asked. “Why does it work on me?”

  “That question hasn’t been out of my head since I heard your voice mail message at the lab,” Nancy said. “We haven’t tested it on people, only inanimate objects.”

  “Why?” Izzy asked.

  “It’s too powerful, and we don’t know enough about it yet. My sense is that the older the person is, the stronger the likelihood of it being dangerous or unpredictable.”

  “Why do you say that?” Izzy persisted.

  Nancy frowned as she thought. “OK, I’ll try to keep it simple. The serum we developed is at the heart of all this. We have deduced that if the serum interacts with certain crystals and stones, it produces astounding results.”

  “I’m with you so far,” Izzy confirmed.

  “Without going into the complexities, we think certain conditions need to be met in order for the serum to work on people,” Nancy went on. “These have to do with cell multiplication, brain development, and method of ingestion.”

  “OK, you’re starting to lose me now,” I said.

  Nancy smiled. “You don’t need to understand all the scientific ins and outs.”

  “You still haven’t explained why it works on Jess and no one else,”
Izzy reminded her.

  “Well, I can’t say for sure, but I’ve got a theory.”

  We waited for her to continue.

  “One day, early on in our research, a couple of things happened that we didn’t think much of at the time, but which I’ve been looking at differently over the last couple of weeks.”

  I raised my eyebrows. “Like?”

  “Like what happened on a certain day just over thirteen years ago. I was running late for my shift. James was carrying a rack of tubes full of the latest version of our serum. The phone rang. I ran to answer it — and we collided. The tubes went everywhere.”

  “You broke all the test tubes?”

  “Yup. I got absolutely covered in the serum, literally from head to toe. I cleaned myself up and left James to deal with the rest of it. I was already late and I had three patients in labor who needed me.”

  I swallowed. “Thirteen years ago. Three patients in labor,” I said calmly. “And my mom was one of them.”

  Nancy turned and looked me in the eye. “Yes. All three gave birth on that shift.” She allowed herself a small smile. “You were the first.”

  I stared at Nancy for a while, trying to figure out exactly what she was telling me. “Are you saying that this serum somehow got into me when I was born?” I asked eventually.

  Nancy nodded. “Obviously, I had no idea at the time. I thought I’d gotten rid of every bit of the serum. I would never knowingly expose a brand-new baby to any form of experimental liquid.”

  Izzy frowned. “So why did you suspect something had happened to Jess?”

  “At the end of my shift, when I took my scrubs off to wash them, I noticed a tiny bit of the serum on the inside of my sleeve. I must have missed it. I had a brief panic, but once I knew all three babies were all right, I stopped worrying about it. I assumed that it hadn’t touched them and, anyway, at that point the serum still hadn’t achieved anything as far as we knew, so I didn’t give it another thought.”

  “Till now,” I said.

  “Exactly. A couple of weeks ago, when we discovered that the serum reacts with crystals, I started worrying again. I remembered your birth, thought about the necklace I’d just given you. I was in quite a state. I even tried to find out from your mom if anything unusual had happened to you.”

  “That night,” I said. “I heard you.”

  “You heard us? I thought you were upstairs.”

  I shook my head and looked down, felt my cheeks burn. “I was invisible.”

  Nancy laughed softly. “I didn’t realize you’d found out anything till I heard your message — I didn’t know if it had had any effect on you. I still had no real reason to think it would have. It’s never worked on anyone else.”

  “Really? No one at all?”

  Nancy’s eyes darkened and she turned away. “Well, there was one time . . .” She held up a hand as if to brush away the rest of her sentence. “But, look, that was completely different, and it was soon after that that we stopped work on the serum — until James started it up again. As far as I know, the serum has never had this effect on anyone else.”

  “How come it didn’t work on you, if you got it all over yourself, but it did work on me?”

  Nancy shrugged. “I can’t be sure, but I think that it must be because you were a baby, not a fully grown adult, when you were exposed to the serum. A brand-new baby’s cells are multiplying and developing much more quickly than an adult’s, making them more receptive.”

  “So it’s always been there? I’ve had this thing in me all my life?” I asked.

  “Probably.”

  “Wow!”

  “You’ve just never known it until you wore a crystal that acted with it to produce an effect. Plus — and this is where it gets a little complicated . . .” Nancy glanced at me. I gave her a quick nod to carry on.

  “Part of my current theory is that the serum works best when it interacts with specific changes in human physiology.”

  “OK . . .” Izzy and I said together.

  “So it only took hold of you as a baby because of the rate at which your cells were multiplying. But since then it has probably been lying dormant until another important developmental stage — the development of your frontal lobe.”

  “Frontal what?” Izzy asked.

  “It’s part of your brain — the part that interacts with the serum to activate its capacity to interface with the crystals. Around your age, the frontal lobe goes through a massive growth spurt. Things are changing in your brain at a really accelerated pace. I think that’s what triggered the serum into acting and why it’s only now that it has become effective.”

  “So what if Jess had come into contact with a crystal when she was younger?” Izzy asked.

  Nancy shook her head. “It almost certainly wouldn’t have done anything.”

  I let out a breath. “Wow,” I said again. What else could I say?

  Nancy pulled on one of her dreadlocks that had come loose and tucked it back under her hairband. “I’d never forgive myself if anything happened to you because of this. If anyone finds out and you get into any kind of bad situation . . . Jess, you know I would never have given you the necklace if I’d had any idea . . .”

  “Of course I do,” I said. “But you would never have gotten this far with your research if you hadn’t bought me the necklace.”

  “I know. It’s all just feeling a little complicated. I want you to know I would never have knowingly put you in this position.”

  I nodded. “I know that. What else is complicated?”

  “Well, James and I could get into massive trouble for continuing to work on this. If it gets out that we’ve continued working on research that the government killed over a decade ago, it won’t look good for either of us.”

  “What would happen?”

  “We’d both lose our jobs, that’s for sure. Probably our licenses to practice at all.” She glanced at our faces. “But, look, you don’t need to worry about that. It’s my problem. You’ve got enough to deal with.”

  “Are you going to tell the doctor about Jess?” Izzy asked.

  Nancy shook her head. “He doesn’t need anything else to worry about. He’s the world’s biggest stress-head at the best of times, and the more he has on his mind, the more it interferes with things.”

  “Interferes? What do you mean?” I asked.

  “Oh, you know. Silly things. Like, for the last couple of weeks, he’s been so wrapped up in his research that he’s gotten quite distracted and absentminded and then he does stupid things — such as forgetting to file documentation or putting vials away in the wrong places. He leaves things out. Some crystals have gone missing, and I’m having to clean up after him just to make sure we keep track of everything we’re doing — and so we can be certain the wrong people don’t get wind of these new developments.”

  I was about to ask who exactly these “wrong people” were when Nancy waved her hand dismissively again. “Anyway,” she said, “I’ve done more than enough talking.” She stood up.

  “Is that it?” I asked. “Are you leaving?”

  “Not leaving, no. But you must be tired of these long-winded explanations. I thought you might like some action instead.”

  “Action?” Izzy asked as we both got up from the bench, too. “What kind of action?”

  Nancy smiled. “You’ll see,” she said. “We need to go somewhere private, though. What I want to show you both is pretty astounding — and top secret!”

  “How about the Meadows?” I suggested. That’s what we called the fields and woodland that lay between the park and the river.

  “Perfect,” Nancy said. “Are you ready?”

  I glanced at Izzy. Her eyes were wide as she pushed her glasses up her nose. “Ready for what, exactly?” she asked.

  Nancy had already started walking away. “Follow me,” she said. “You’ll find out when we get there.”

  Nancy led us to a small clearing in the Meadows. Around us, grass rose as h
igh as our waists. “Help me pat it down,” she said, stamping her feet on the grass to create a flattened space.

  Once she’d decided we had enough room, she bent low and opened her bag. I went over to look as she pulled things out of it: a metal bowl on a wire stand, a piece of cloth with about ten different crystals wrapped in it, and a thin glass bottle filled with clear liquid.

  “You just happen to carry these things around with you?” I asked.

  Nancy laughed. “No. I just happened to think you might want to see some of this.” She looked from Izzy to me. “Ready to get started?”

  “We’re ready,” I said.

  “Good.” Nancy bent down and set to work. She picked up one of the crystals. It was a small bunch-like shape in deep green. It looked like a mini broccoli. “This is called malachite,” she said. She opened the bottle and poured some clear liquid into the bowl. “I need to use this sparingly,” she said. “We don’t have much left. But I’ve got enough to put on a good show for you.”

  Then she dropped the malachite into the bowl. “Watch,” she told us.

  Nothing happened for a moment. Then the liquid began to fizz gently, bubbling and clouding over. The malachite bounced around in the bowl as the bubbles formed.

  “Look!” Izzy said, gasping as she pointed at the bowl. The crystal was getting bigger. Within half a minute, it had grown to at least three times its original size.

  “It’ll crack the bowl!” I said.

  “It’s OK. It doesn’t get bigger than this,” Nancy replied. We watched as the bubbles gradually subsided and the liquid calmed down. Then Nancy reached in and pulled out the malachite. She handed it to Izzy. It was nearly as big as her hand.

  “That’s amazing,” Izzy said, turning to me. “Do you want to hold it?”

  I reached out for the stone, but Nancy put a hand on my arm to stop me. “Wait!” she said.

  “What’s up?”

  “We’ve done some tests, so I’m sure there’s nothing to worry about, but I want to explain something about our results before you touch it, OK?”

  “OK,” I agreed.