Thank you so much for joining us on Nora “Sierra” Byrd’s first adventure.

It’s been a real pleasure to entertain you over the last few hours. We hope you enjoyed spending time with Byrd and her crew as much as we did.

Collaborating on this book has been a unique and rewarding experience. It brought together our different writing styles, creative ideas, love of exotic settings, and gave a character from Luke’s Eden Black series a chance at her own adventure. 

In case you didn’t know, Nora “Sierra” Byrd first made her entrance in The Atlantis Agenda, when Eden, Baxter, and Athena lose their helicopter in Mexico City. Stranded and in need of a way out, they search the area and stumble across Byrd’s Flight and Parachute School, a few miles north of the city. With no better option, they break in under cover of darkness. They head for the hangar, planning to “borrow” a plane when something unexpected happens.

* * *

“At least someone thinks what’s inside is worth protecting,” Athena said, stepping alongside Eden. The beams of their lights swayed through the gloom.

“That shouldn’t be an issue,” Baxter said. “We’ve got a tire iron in the truck. We’ll be in there in a few seconds.” 

“You’ll do no such thing,” came a voice from behind them. “Now turn around really slowly. I wouldn’t want you to get shot accidentally.”

Eden gritted her teeth. She looked up at the large hangar doors in front of them, blocking their path. She glanced left and then right. The voice sounded close behind them, trapping them against the doors. 

As though reading Eden’s thoughts, the voice came again. “I’ve got the business end of this Remington 870 pointing right at your backs.” The mystery assailant pumped the gun, as though proving the threat. “I won’t tell you again. Turn around now.”

Eden glanced quickly at Baxter and Athena, then nodded almost imperceptibly. Together, slowly, the three turned around.

The sight of their aggressor took Eden by surprise. A woman in her early middle age looked the three of them up and down. She had a great beehive of black hair tied up on her head. She wore the overalls of an Air Force pilot, open at the front with a red tank top beneath. There was something strangely glamorous about the woman, Eden decided. Her large, brown eyes darted from Eden, to Athena, and then to Baxter.

“Now then, I think you had better tell me why you’re breaking into my airfield in the middle of the night,” the woman said, raising the gun to impress upon the three the fact that she wasn’t asking.

And the character of Nora “Sierra” Byrd was born. 

* * *

Some of you sharp-eyed readers may have noticed that the “Sierra” part of her name is new. That was John’s idea—he felt that just calling her “Nora” didn’t quite have the punch you want in an action story. He was right, of course. At some point, Luke plans to go back and sprinkle a few “Sierras” into the earlier books. Until then, chalk it up to one of those quirks that come with spin-offs and long-running series.

Now comes one of our favorite parts of the book, telling you the truth behind the story.

The Shadow of the Sunstone is, as you now know, a story about the search for eternal life. It’s a quest as old as human history—and though ours may involve vintage aircraft and a quick-witted pilot, the subject matter is anything but lighthearted.

Humanity has chased immortality for centuries, often with grim consequences. From sacred springs to deadly elixirs, the pursuit has always demanded a steep price.

In 16th-century Hungary, Countess Elizabeth Báthory reportedly bathed in the blood of young women, believing it would preserve her youth. Chinese emperors ingested mercury in the hope of becoming immortal—only to find an early grave. Across medieval Europe, alchemists obsessed over gold-laced tonics that promised eternal life, but delivered only slow, painful deaths.

The idea that eternal life might come from a plant isn’t new either. In ancient Greece, the mysterious herb known as silphium was famed for its near-miraculous properties. Used as everything from a cooking spice to a fever remedy—and even as a contraceptive—it was so valuable that Julius Caesar is said to have stored a thousand pounds of it in Rome’s treasury alongside gold.

But silphium resisted cultivation and by the first century C.E., it was so rare that Pliny the Elder wrote of a single stalk being discovered—promptly delivered to Emperor Nero as a gift. For centuries it was believed extinct. Only recently has a researcher in Turkey claimed to have discovered a plant that’s strikingly similar, growing in the Anatolian highlands.

Of course, no legend of eternal life looms larger than the Philosopher’s Stone. Said to transmute base metals into gold and produce the fabled Elixir of Life, the Stone promised both wealth and immortality. Among its most famous seekers was Nicolas Flamel, a 14th-century Parisian scribe whose name later became synonymous with alchemical success. Did he truly unlock the secret? Historians say no. But the myth persists—in dusty manuscripts, whispered conspiracies, and the occasional burned laboratory notebook. Some stories are simply too alluring to die—which is, we suppose, the immortality us writers hope for!

The ancient Egyptians took a more engineered approach. They didn’t merely hope for life after death—they designed for it. Through the art of mummification and the construction of mathematically precise pyramids, they sought to secure the soul’s journey into the afterlife. Pharaohs consumed rare herbs and minerals believed to prolong life, including the sacred blue lotus—thought to expand consciousness and open the mind to the divine.

Their Book of the Dead was a manual for the soul’s passage, filled with incantations, rituals, and passwords meant to guide the departed through the perils of the underworld. For the Egyptians, death wasn’t the end. It was a doorway—and preparation was everything.

So, has anyone ever truly found the secret? We doubt it. But some places do seem to come close.

On the Greek island of Ikaria people live remarkably long and healthy lives. Here, longevity isn’t rare, it’s expected. Locals climb steep hills well into their nineties. Their diet is rich in wild greens, legumes, olive oil, and herbal teas made from native plants—some of which may have echoes of the ancient silphium. Whether it’s biology, environment, or something more elusive, people on Ikaria simply live longer.

Maybe the real secret isn’t locked in a tomb or hidden in an elixir. Maybe it’s in the hills, the herbs, and the pace of a simpler life. Tempting, isn’t it?

* * *

The idea of the Mentor and his shadowy cult was a fascinating one to explore in this story. While fictional, the group draws heavily on real-world influences—especially some of the more bizarre spiritual movements of the 20th century. One such inspiration was The Source Family, a Los Angeles-based commune that emerged in the 1970s.

They wore flowing robes, practiced esoteric rituals, chanted in invented tongues—and ran a health food restaurant on Sunset Boulevard. At the center of it all was a man named Father Yod: a former jujitsu instructor who reinvented himself as a spiritual leader and self-declared prophet.

Charismatic and deeply unconventional, Father Yod married more than a dozen of his female followers, presided over daily meditations from a throne, and led the group’s psychedelic rock band, YaHoWha 13. They lived communally in a mansion in the Hollywood Hills, where spiritual enlightenment mixed freely with countercultural experimentation.

The story took a darker turn when the group abruptly relocated to Hawaii, hoping to build a utopian society. Things unraveled quickly when Father Yod attempted to hang-glide off a cliff—without any training—and died. He claimed he “knew it was his time to ascend.” It’s strange history. But it’s real.

And as we crafted our fictional cult, we kept coming back to this unsettling truth: people can be drawn into the orbit of a powerful leader when they’re desperate for meaning. Sometimes, that search leads to beauty and healing. Other times, it leads straight off a cliff.

* * *

A note on the aircraft featured in this book

Every plane that appears in these pages is real, drawn from aviation history—but we’ve taken liberties. Some flight paths, maneuvers, or mechanical feats may stretch the bounds of what’s technically possible. For the aviation purists reading, we offer a sincere apology—and a thank you for your patience. Story sometimes takes the stick.

The real star of the skies, though, is Byrd’s aircraft: a lovingly restored Douglas C-47 Skytrain. Originally designed as the DC-3, this twin-engine, all-metal transport first took flight in the 1930s and revolutionized civilian air travel. When war broke out, the U.S. military adapted the design for combat operations, reinforcing the airframe, adding cargo doors, and equipping it for rugged conditions. Thus, the C-47 was born.

She could carry 6,000 pounds of cargo or 28 fully equipped troops. She wasn’t built for speed, but for resilience. Pilots came to trust her without question—she was tough, dependable, and forgiving in a crisis. Even when riddled with bullet holes or battered by weather, the C-47 had a reputation for bringing her crew home. Affectionately known as “The Gooney Bird,” she might have looked awkward on the runway, but in the air she was a workhorse—steady, capable, and essential.

Her resume is remarkable: dropping paratroopers on D-Day, flying treacherous supply routes over the Himalayas to support Chinese forces in World War Two, and running missions during the Berlin Airlift, where she helped sustain an entire city during the Soviet blockade. Today, she still flies in private hands and museums around the world—a living symbol of endurance, craftsmanship, and courage.

This book also incorporates our love of travel. Both of us have spent years travelling all over the globe, and love putting that into our stories. Set in the Caribbean with action across Mexico, this story is a combination of real settings and fictional ones. The island on which Byrd’s flight school the Isla de la Fortuna, and the island on which Hutchins and Wall first discovered the ancient human remains the Isla de la Vida Eterna, are both fictional. The Mexican towns, of course, are real and we’ve done our best to capture the vibrancy of these places. 

As for what comes next—well, Byrd’s just getting started. There are more secrets buried in forgotten places, more myths waiting to be cracked open, and more flights into danger than she’d probably like. At that time of writing we’re already plotting the next chapter in her story, and if you’ve enjoyed this mix of legend, history, and high-stakes adventure, we think you’ll want to be there when the wheels leave the ground again. Until then, keep your eyes on the horizon—and never stop chasing adventure.

Thanks for your company, see you on the next one! 

Luke and John 

May, 2025.