"The only thing that kept me going was Jeff. He returned my call at just the right time. If I believed in such things, I would have thought he was sent to me, an angel. He convinced me that the nardo holds the key to saving a lot of lives."

Alyssa gave me a determined look, and I suddenly felt that I knew her. She was as driven as I was.

"Help me find this goddamn plant," she said.

A few moments later, we were breezing along the Campania coastline again as if nothing had happened.

"Why do you think it is spikenard?" I asked.

"Because several species of spikenard are described as nardo in an ancient text," she said. "The book is De Materia Medica. The author, Dioscorides. This man was a traveling physician with Nero's army, and even today De Materia Medica is still considered one of the most complete reference books for organic medicine in history. It is the closest thing we have to a contemporary eyewitness account of the plant species we are looking for.

"Furthermore," she went on, "this text was never 'rediscovered.' It never left circulation from the time it was written in the first century CE. It was the first written account of medical botany and the extant authority on herbal medicine all the way through the sixteenth century. For almost two millennia, it was the Physician's Desk Reference, utilized consistently by the best doctors in the world. So if this text says nardo is spikenard, I'm inclined to go along with it."

We turned off of the highway and wound our way up a short hill. Moments later, we pulled into a large parking lot at the base of Mount Vesuvius. A few buses and vans were also in the lot, and tourists were wandering around, photographing the volcano.

"I hope you're in shape," Alyssa said, examining the mountain from below.

"I'll race you," I challenged.

She was right. The climb was steep. But I estimated it would take no more than about fifteen minutes to reach the top. I charged forward, breathing steadily. Alyssa kept pace with me, and we quickly overtook a family who had paused for a small child to rest. I could hear Alyssa's breathing become somewhat labored as we climbed. She was in good shape, but not a runner like I was.

"Much of Dioscorides' knowledge came from his own travels during campaigns with Nero's army-but much of it did not. His text mentions plants from all regions of the world, many of which Nero's campaigns never brought him to. Dioscorides describes many, many species that there is no way he saw first-hand."

Alyssa glanced behind her to confirm that the nearest tourists were out of earshot. "Experts agree that these species were discovered on the campaigns of Alexander the Great. Dioscorides must have learned of them from Alexander's records. So isn't it interesting that Cleopatra destroyed these records long before Dioscorides was ever born."

We reached the top of the volcano, and I stood for a moment to stare into the mouth of the killer. The crater looked so quiet, so innocent, but it is still an active volcano.

I imagined the destruction that Mount Vesuvius had unleashed in 79 CE. And I realized that it would happen again. I looked toward Naples and the bay. The boats. The castles. The shops, the restaurants, and the homes. At any moment, it could all be gone.

"What are you talking about?" I asked Alyssa, returning my attention to our conversation.

"The great library of Alexandria," she said. "It was the largest database in the ancient world. Ptolemy I inaugurated the library with the texts of Alexander the Great. And every subsequent ruler in the Ptolemaic dynasty continued to add to it.

"By law, visitors to Alexandria were forced to lend any works that the library did not already contain to be copied; the originals were not always returned. They sought to accrue copies of every text written in Greek, Aramaic, and Egyptian. Interpreters were employed to translate the documents that were not written in Greek.

"Two hundred fifty years later, Cleopatra inherited this library. By then, it was legendary, containing approximately seven hundred thousand papyrus scrolls. But neither the library nor the adjacent museum was open to the public. They were used for research purposes by museum members, mostly members of the royal family and their entourage."

"So the Ptolemies created the knowledge capital of the world and hoarded it amongst themselves?" I asked.

"Exactly. The Ptolemies were not just curators of knowledge. They were pirates. But because they kept the books to themselves, an illegal book trade grew up around the Alexandria library. It was through this underground network that many texts from the ancient world-real and fabricated-were made available to the general public over the centuries. The lack of any regulation in the trade has dramatically complicated the identification of genuine versus bogus texts.

"Within the Alexandria library were the greatest achievements in literary scholarship and applied sciences, including the first documentation of what is now established scientific method. There were many works of Herophilos and Erasistratos-third century BCE doctors-revealing fundamental discoveries concerning anatomy, which they made through dissection of corpses and criminals.

"Cleopatra herself was rumored to have written dozens of books on a variety of subjects, ranging from weights and measures to cosmetics to magic. Yet, none of her writings can be found today, with the exception of the Herculaneum document I myself discovered. And the majority of texts that existed in the Alexandria library during Cleopatra's reign, including the descriptions of plants discovered on the campaigns of Alexander the Great, were lost on her watch."

I reached down and grabbed a handful of earth and then allowed it to slip through my fingers. A brisk breeze carried it, and it billowed to one side before falling to the ground once again.

"How could the 'highly ambitious' Cleopatra let that happen?" I asked.

"I think she arranged it," Alyssa said. "The library was burned down by her lover, Julius Caesar."

I pulled a ziplock bag from a shopping bag and opened it. I grabbed another handful of soil from beneath my feet, dropped it into the ziplock bag, and sealed it. I then withdrew a permanent marker from the shopping bag and labeled the sample.

"May I ask a silly question?" Alyssa asked.

"Sure."

"Instead of gathering small samples, wouldn't it be better to collect large quantities of dirt and attempt to grow the plant? Wouldn't that be the best way to find out what compounds are generated?"

"Of course," I said, "once we find the plant. But right now we aren't even sure what it is. And in the meantime, I can start with a basic analysis of the composition of the soil. I can do this with very little material."

What I did not tell Alyssa was that I had no intention of growing any plants. She was right that cultivating plants under the appropriate conditions was the most logical path forward. But it was not an option. There was no time. My uneasy alliance with a skeptical mortician was over. And my daughter could not wait.

My alternative was to independently analyze the elements within the soil, the water, the air, and the plants-if I could get my hands on the right ones. It was a dirtier approach, but a much quicker one, and there was a chance that, if I was very lucky, it would yield the isotope.

I already knew what to do with the isotope if I found it. I would examine its interaction with the HER2 protein on human cells. And, if I was very, very lucky, that interaction would block the cancer shared by my husband and my daughter.

When I touched one of the nardos, a gentle warmth ran from my fingertips to my heart, like a quiet flame in the blood of my arm.

I moved quickly. The work was mindless, and, as I carried it out, I reflected upon what I knew of the isotope and the nardo.

"I think the isotope might have some effect on the heart," I said, bending down to scoop a blackened patch of soil from the center of a more brightly colored area. "But Cleopatra didn't leave us as many clues to it as I would have liked. Why would she burn her own library down?"

I sealed the ziplock bag containing the sample and scrawled a descriptive label onto the plastic. Then I stepped a few yards further into the crater. Alyssa followed.

"I'm not sure," she said. "But it certainly seems to have been deliberate. It happened when Cleopatra joined forces with Caesar to battle her brother Ptolemy the Thirteenth to the death.

"The hypothesis is that the fire was a strategic military maneuver, meant to frustrate a traitor's attempt to communicate by sea, and that the library burning down was just an accident. But the fact is that Caesar set fire to his own ships, and the fire spread rapidly to the docks and the Alexandria library. The seven hundred thousand papyrus scrolls within were decimated."

Deeper within the volcano's crater, the soil was rockier, lacking the fine sandy texture of the well-trodden dirt on the tourist paths. I collected a few more samples.

Alyssa continued. "We know the importance of the library to Cleopatra by the fact that Antony's wedding gift to her fifteen years later was two hundred thousand new scrolls to re-populate it. Yet at the time, she didn't seem bothered by the fact that her lover had destroyed two hundred fifty years of accrued knowledge and information. Indeed, she followed Caesar to Rome twice in the next four years with their son, Caesarion, who had been born within a year of Caesar and Cleopatra's first meeting.

"And remember, all this time Caesar was married to another woman. His wife was Calpurnia, the daughter of Lucius Calpurnius Piso Caesoninus, who was the owner of the Villa dei Papiri in Herculaneum. And that, of course, is where the nardo document was unearthed.

"I believe Cleopatra and Caesar staged the fire that consumed the Alexandria library. They had obviously already removed important works from this library and hidden them elsewhere, including the nardo document."

I motioned for Alyssa to follow me, and we began walking toward the other side of the crater.

"So..." I said. "Cleopatra witnesses an extraordinary medical phenomenon in the nardo-"

"And she writes about it in Egyptian," Alyssa added, "to conceal it from her peers who don't speak the language."

"And then she moves the document from her own personal library in Alexandria into the Herculaneum villa of Caesar's father-in-law, just before Caesar burns the Alexandria library down," I said and bent down to collect another sample.

"Yes," Alyssa said. "In fact, I now know of three locations containing hidden documents from Cleopatra's reign. Two, of course, are the Villa dei Papiri in Herculaneum and the crocodile cemetery in Fayoum, Egypt. There was also a daughter library located elsewhere in Alexandria. Remains of that library still exist. Who knows how many hiding spots may have existed worldwide?

"I am sure that by the time of Dioscorides at least one of these sites had been found. Dioscorides was Roman. He would have had full access to the Egyptian archives after the Ptolemaic dynasty fell to Rome.

"It is clear that Dioscorides was a student of Egyptian medicine. His text, De Materia Medica, is full of ancient Egyptian remedies. He wrote of nardos and of some of their medical uses. But he wrote nothing about their potential to treat cancer, which means he did not know of the phenomenon described in the document you read."

I ran through the sequence of events in my mind once again. When I spoke at last, I spoke with conviction. "Of course he didn't. He couldn't. The document was trapped beneath the ash in the Villa dei Papiri throughout his lifetime."

A deep cave there was, yawning wide and vast, of jagged rock, and sheltered by dark lake and woodland gloom, over which no flying creatures could safely wing their way; such a vapour from those black jaws was wafted to the vaulted sky whence the Greeks spoke of Avernus, the Birdless Place.

-The Aeneid Virgil (7019 BCE)

Chapter Thirteen.

An hour later, the Solfatara crater gaped and belched at me like a suppurating wound. "I agree with Dante Alighieri," I said. "This place is the gateway to Hell."

The stench of sulfur invading my nostrils was overwhelming, and that was just the beginning of the vileness of the place. Thick black boiling mud burped globs of putrescence. As I watched, a steam geyser spewed to a height of nearly three feet from a yellowed mouth. When the wind shifted, the geyser turned toward me, and the onslaught of sulfurous vapor was multiplied.

"Shit," I said under my breath when I remembered what I had come there to do.

Alyssa looked amused. "I dig up mummies," she said. "This is all you."

Rickety waist-high fencing separated Alyssa and me from the volcano, and I could not believe that the word "dormant" was used to describe it. I wandered for a few moments through the area that was open to tourists. As I did, I reached down and touched the earth with a flat hand, feeling around to gain several reference points. Some spots were considerably warmer than others. And then I understood why Alyssa had included a collection of small microwave- and oven-safe containers when we stopped for supplies. Ziplock bags would melt.

"I'm glad there are no other tourists here," I said. "I have no desire to watch someone's three-year-old follow me into an abyss of boiling quicksand from which I'm not guaranteed to emerge." I took a deep breath and jumped over one of the fences. The closer I came to the thermal mud lake, the more I could feel its heat radiating up my legs beneath the cuffs of my jeans. When my one-day-old sneakers began to sink, and then stick slightly, and then produce audible sucking noises as they came out, I decided I had gone far enough.

"This is why I don't do field research," I muttered under my breath, and I quickly dunked one of the small heat-resistant containers into the mud. The container did not melt, but I could feel the intense heat through it. Earth's vomit, I thought and popped a lid onto the container.

"Does it feel like Satan is reaching up to pull you into Hell?" Alyssa shouted from the safety of the other side of the fence.

"This is Hell," I fired back.

The momentary cessation of movement had sunk my feet even deeper into the mud, and I really did wonder for a moment if I would be stuck there permanently, like a mafia informer in cement shoes. After a brief struggle, I yanked myself away from the hungry, angry, sucking mud and returned to the safer side of the fence.

I repeated the procedure at the bocca grande, or "large mouth"-the largest of Solfatara's steam geysers. Although the geyser shot only a couple of feet high, it projected steam at scalding temperatures. The day was windy, and I was approaching a boiling geyser with a plastic container and the sleeve of a sweatshirt as the only protection for my arm.

"You look like someone offering a sardine to Jaws!" Alyssa shouted, and she was giggling.

Fortunately, the earth around the bocca grande was solid. During a momentary stillness in the breeze, I rushed in and hastily gathered a sample of the steaming emission. Without bothering to cap the container, I leaped away as quickly as possible, hoping fervently that the wind would not shift.

"OK," I said to Alyssa, finally breathing easily again. "I guess that does it. I need a shower."

Alyssa smiled. "Don't you want some water from the River Styx?" she asked.

"The name Lago d'Averno is Greek," Alyssa said. "It means 'lake of no birds.' It was once believed that birds flying over the sulfurous water would drop out of the sky, dead from the fumes. Of course, we have now confirmed the presence of fowl, but the lake is... well, foul."

Nonetheless, I found the lake infinitely more pleasant than Solfatara. I was happy to discover that it was easily accessible and even populated by a handful of brave swimmers. It was also surrounded by lush greenery, and I ordered myself to cross-reference the plant life-clearly adapted to grow in highly concentrated sulfur-with anything that could be referred to as nardo. I did not see any lavender. I certainly did not see any spikenard.

After I gathered some water from the lake, Alyssa led me back toward the parking area and then beyond it for a couple hundred yards. "This is where the real entrance to the underworld is supposed to be," she said. "It's called Sybil's Grotto."

A man stood at the entrance, and Alyssa negotiated with him for a few moments in Italian before he led us into an underground passage. As the guide led Alyssa forward, I allowed myself to fall behind. I scraped a small pile of dirt from the floor and a bit from the walls of the tunnel.

We stepped back out into the daylight, blinking against the glare, and Alyssa thanked the man before we walked away.

"There are several ruins around here," Alyssa said, gesturing with her arms as we walked. "There's an old Roman temple, an arch, and the ancient city of Cumae. Of course, the spots we have already been to are probably more important for your research. If we need to gather soil from every Roman ruin in the area, we're in trouble."

Nodding agreement with her, I asked, "What now?"

Alyssa chuckled. "Do you dive?"

"Are you serious?"

"I am. Just a couple miles away are the ruins of Baiae. It was a summer resort for the Romans, and a villa still standing there was the summer home of Julius Caesar. Fairly extensive ruins remain, including a bath complex and a more modern castle. But the majority of the site is underwater. You can see it via glass bottom boat tour, or you can take a diving tour."

I thought for a moment and then said, "Yes, I dive, but I don't think it's worth it. It's one thing to gather the native soil of an area by collecting samples. It's another to hope that the composition has remained unchanged after two millennia of being submerged in seawater."

"But they haven't been underwater for two millennia," Alyssa said. "The bradyseisms-uplift and subsidence events-that submerged much of the city only happened in the mid-1500s. Many of the ruins were discovered from aerial photographs of the region taken during World War II. So Baiae, now an underwater park, has only relatively recently become available for exploration and is still very much preserved.

"And that's not the only reason for you to gather samples there. The bath complex was originally built on a natural mineral spring of highly reputed medicinal value. These baths were where doctors in Caesar and Cleopatra's time sent patients for treatment. I wouldn't be surprised if Cleopatra herself had frequented them for medicine. And the sources are still active, still producing the same medicinal output. But it is all under water."

So I dove into a secret world beneath the sea, a world unassumingly frozen in time and space.

The tour for advanced scuba divers began with a brief refresher course on diving, followed by a description of the sites we were about to swim to. By the time my English-speaking guide finished his monologue, I could not wait to get into the water. But the tour began on the ground.

The ruins of Le Terme di Baia, the "Thermal Baths of Baiae," remain above sea level. Had I been passing through the largest and most important medicinal bath complex of the ancient world on virtually any other day of my life, I would have been fascinated. Instead, I was looking at my watch, and then out at the water, and then at the rapidly lowering sun, anxious to start diving while there was still sufficient daylight. But once we boarded the small boat that would take us to the dive, the wait was only minutes.

Conversation necessarily ceased when we dropped into the water, instead becoming a compilation of improvised hand gestures. "Sign language is genetically programmed into Italians," Alyssa had quipped. "But you might need an interpreter."

Our guide led us first to the nymphaeum. He had told us that the amazingly intact collection of statues was a tribute to the lineage of Mark Antony with Octavia, his first wife. The one Cleopatra supplanted.

Alyssa had filled in other details more pertinent to our search during the boat ride. Octavia was also the sister of Octavian, the rival who ultimately defeated Antony and Cleopatra, leading to their suicides. Antony's daughter with Octavia was Antonia Minor. Antonia's great-grandson was Emperor Nero, the emperor under whom Dioscorides would document the botanical discoveries of Alexander the Great in De Materia Medica.

I swam in a circle around the life-sized statue of Antonia, marveling both at its preservation and at the fact that I was observing it accompanied by a school of fish. Contrasted with the blue water surrounding her, Antonia's white marble figure shone, illuminated by the few rogue sunbeams that penetrated through the natural filter of the water.

Tiny rivulets of bubbles flowed upward from the earth like the artificial aeration mechanism in a modern aquarium. I pulled a ziplock bag from the sleeve of my wetsuit and inverted it over one of the sources. I held it there until it filled with air and then zipped it shut.

Antonia was surrounded by several other equally well-preserved statues, and the other four people on my tour, including Alyssa and the guide, swirled curiously around each of them for a few moments.

After we left the nymphaeum behind, we passed over a series of large marble slabs and several amazing mosaics embedded in the sea floor. These had been walkways and patios. Our guide called attention to the structures by passing a hand over each, clearing away the silt that had settled onto the black, white, and multi-colored marble pieces.

Then he brought us to the summer villa of the man whose main residence was the Villa dei Papiri. The summer residence of Lucius Calpurnius Piso Caesoninus was decadently expansive. Our guide motioned for the four of us to follow him to a thinly covered expanse of lead pipe. He brushed a hand over it, and the silt feathered away, revealing the inscription in Latin letters: L.PISONIS.

Near it was an enormous courtyard. A series of arcades and passages led us through several private rooms and, eventually, to the private thermal mineral baths belonging to Lucius Piso. As I had near the statue of Antonia Minor, I collected several samples of the gases bubbling up from the sea floor.

We spent a great deal of time exploring the expansive Portus Julius, which covered more than ten hectares and featured mile-long canals and tunnels connecting Lake Avernus, Lake Lucrine, and the city of Cumae. It was this site that had first been detected in the intelligence photographs of World War II.

But I was most interested in the "Smoky Reef," so called because of the fumaroles, columns of gaseous bubbles escaping from the sea bed.