The i-Ching consultations depicted in The Girl from Wudang are real. As I was writing the chapters, I asked the coins the questions the characters were posing and used whatever the book said. More than a gimmick or a superstition, it was just another demonstration, maybe the most literal but not even close to being the most radical, of how stories develop themselves around us.

One of the main issues in my first drafts was pointed out by my amazing beta-readers Talita Carneiro and Sam Glynne: Yinyin’s motivation had to be really strong to take the risk of placing micro-bugs in her brain. They were right, and that question haunted me for months. In the meantime, for reasons unrelated to this book, I had the pleasure of meeting Paul Li, neuroscientist and professor at Berkeley, where he teaches cognitive science—a mix of neuroscience, philosophy, and technology, as he explained. I thought I had found a golden ticket when I heard that, but then he told me he’s also Chinese and a Muay Thai fighter!

Well, as I abused his generosity, Professor Li answered dozens of questions related to neuroscience, helping make the science as solid as possible, given the freedoms novelists are allowed to take. “Sci-fi sometimes takes leaps scientists will only confirm decades later,” he said. But there was one thing bothering him. The lack of fear of side effects. Since I had heard that before, I asked him what they would be and, more importantly, how the scientists would deal with them. It was he who recommended the oxygen tank to replenish the exhaustion the experiment would cause. Which led to the next part of this puzzle.

I had just finished the second draft and was taking a break to think about the main issues before I started to edit the book again when a dear friend, who will remain unnamed because she doesn’t want to expose herself that much, told me about the torturing headaches she had been experiencing. Suicidal headaches, people call them. They’re that terrible, and the scenes in this book do not display the true horror this condition induces. My friend made me watch videos of people in crisis mode that broke my heart. We talked about it at length. I was trying to help, asking my M.D. brother for advice, searching for contacts at good headache clinics, browsing the subject through deeper and deeper digital rabbit holes. Given all the medical minutiae in this story, it helps to have a brother who is a surgeon in Brazil, always ready to respond to my late-night requests, early in the morning for him. Dr. Pedro Ricardo Milet, I am so proud of you, and so thankful as well. During one of these study dives, I saw a patient trying to manage a crisis with an oxygen tank, and everything clicked. The motivation, the management, the stinging theme that was already present throughout the book. Seemed like the Dao was trying to help.

The Dao, being timeless and absolute, awarded me with friends and connections, and even strangers who helped when they had very little to gain.

Including my Chinese friends who gave me so many careful explanations about their culture. Yoyo Chu, who helped me in a creative workshop I taught in Beijing years ago, was kind enough to read the first drafts of the manuscript and send me her careful and thoughtful notes. It helped that she is also very passionate about Daoism and the philosophical elements of this book. I got “lucky” again. The same way I did for all the insights into modern Chinese culture coming from Anthony Tse and Polly Chu on my trip to Shanghai in 2018, when I also received some wise advice about Chinese health traditions and also China’s entertainment landscape from Fremantle’s Vivian Yin.

To give back to the Chinese community, I counted on my friends Kevin Swanepöel, Ma Chao, Celia Wen and the crew at The One Show China for allowing me to teach my perspective in storytelling to Chinese youth, a good way for me to give them something in return for all I have been getting from their culture.

My family is the greatest of blessings though. Starting with Lo Braz, my wife whose support helped me deal with the insecurities so natural to the adventure of trying to write a book in another language, and my son Francisco who always inspired me to want to be the best version of me and never shied away from being a sounding board to my most absurd ideas. Having a son with such a sensitivity for stories and characters is a luxury I couldn’t have wished for.

Same with a legion of fighters who shared their perspectives, techniques and motivations with me. Starting with James Nottingham who so carefully revised all the fighting language of the manuscript. To my old friend Andrea Cals, Gracie Jiu Jitsu fighter in our native Rio de Janeiro, ground fighting not being my specialty, it was great to be able to count on your patient experience. Amber Staklinski, martial arts instructor and one of the names behind the popular online channel Aperture Fighting, brought valuable insights into the female fighter mindset. The fierce (and borderline scary) Wudang Daoist, composer and fighter An Ning from Shanghai, gave me chills by allowing me to see my character in flesh for the first time and giving me a clear sense of what Yinyin would and wouldn’t do or think. Amateur MMA fighter and litigator Julie Cohen and my Brazilian Jiu Jitsu training partner Sharon Meguira helped sharpen Yinyin’s commentary about being a woman in the traditionally male world of fighting. Thanks to Gabi Garcia, possibly the most accomplished female Brazilian Jiu Jitsu fighter of all time (and still one of the top ones when considering both men and women) for her thoughts on her confidence to fight men. Two-time Kick Boxing World Champion Vanessa Romanowsky, at that time a badass 14-year-old helped me grasp the mind of a young woman so dedicated to her skills. MMA legend Chris Cyborg offered precious tips on the realities and challenges of the coed side of combat sports, while five-time world champion in Brazilian Jiu Jitsu Kyra Gracie helped me develop a deeper understanding of the mission of teaching women to defend themselves, a process that got even deeper after my interactions with her cousin Rener Gracie (and indirectly with his brother Ryron and his wife Eve Torres) as he unpacked the system they teach at Gracie University and the empowering effects of those skills in the life of the students.

Other friends went through the torture of trying early versions before the first draft, when this story was still an annotated outline lacking motivation, structure, and pace. Alma Har’El, Paulo Melchiori, Rob Lambrechts, Luke Ryan, Abigail Booraem, Denise Corazza, Thais Lyro, Stanlei Belan and Alisa Brooks.

Some people helped me reach some of the specialists I talked to, and no one more than mixed martial arts icon Rodrigo Minotauro. Can’t thank you enough! But I can’t forget other friends who sent me on the right direction too, such as João Daniel Tikomiroff, Andrés Balé, Ana Luísa Ponsirenas, Vania Amaral, Michael Fanuele, Natasha Caiado, Paola Colombo, and Billie Goldman. Then the few more who helped with encouragement, advice, and polishing the manuscript, including Tom Perrota, Monica Rector, Lisa Gallagher, Meghan Ward, Mary Kole, Susan Barnes and Rebecca Brewer. I would even include here the subtitles teams at Netflix, Hulu, HBO, and Disney Plus — being a foreigner daring to write in his second language, the real time matching of action and closed captions helped me quite a lot. I wish I knew some of you to give you a big thank you.

On the scientific and technological side of my learning quest, I must acknowledge Dr. Marco Iacoboni, director of the Neuromodulation Lab at UCLA, for the tireless advice on my design for the nanobots. Professor Shogo Hamada, Department of Biological and Environmental Engineering at Cornell University, gave the advice on the biomaterials that became part of the nanobots “architecture.” Sashi Jain, innovation specialist at Intel, checked my designs and pointed me to the field of neural lacing, which unlocked a whole new universe of study and sources I could research. Award-winning tech genius John Tubert; Rodrigo Siqueira, deep learning specialist at Microsoft; and über geek Rafael Gaino shared invaluable tips too, from the deep worlds of Artificial Intelligence to the cubic realities of some of the games I used as a reference. On the marketing side, I had the luxury of counting on the sharpness of the Pereira O’Dell team, especially Mona Gonzalez, Lyndsey Fox, Breanne Brock, and Kate Wadkins; plus the practicality of Octavio Maron and the experience of André Quadra.

In the field of neuroscience, I must highlight Dr. Theo Marins, Brazilian researcher at D’Or Institute, who helped me imagine possible realities of living with a high bandwidth connection between brains, and the also-Brazilian Dr. Eliza Harumi, researcher at Hospital Albert Einstein, who enlightened me on the potential implications of meditation in the connected brains.

On the philosophy part of the research, there are also loads of people to thank. Professor Barry Allen (McMaster University, Canada, author of Striking Beauty) shared his invaluable advice and bibliography about philosophy and martial arts. Bestselling Daoist writer Deng Ming-Dao spent hours helping me understand the nuances of the cultural differences between life in China and America and, of course, gain a deeper understanding of the Dao. Ravi Campos shared lots of references and articles on human rights for an AI-powered world. Eric Schwitzgebel, professor of philosophy, University of California at Riverside, advised me on the ethics of designing AI creatures. Berkeley statistics and deep learning professor Bin Yu inspired me with insightful conversations on the flaws of Artificial Intelligence, philosophy, arts, the nature of humans and machines and the fuzziness of science.

I mustn’t forget my dear friends at Pereira O’Dell, whose names I stole so I could like my characters better—please know the personalities I created have nothing to do with my judgment of the real you, especially my friend and business partner of almost 20 years, and one of the most generous men I know, Andrew O’Dell. I’m lucky to have met each one of you.

Luck also happens when your other projects allow you to have big and small interactions with people much smarter than you, who can enlighten your thinking with ideas and inspiration. In my case, these encounters included Werner Herzog, who showed me how to look at technology as if I’m staring at a beast; Kurtz Weil, head engineer at Google, who gave me a glimpse of the future of human gods and the first dive into the clash between artificial and natural cognition; Patrick Hunt, professor at Stanford, who shared dark tales of the Bible that illustrated some of my scenes; Nicholas Negroponte, founder of the MIT Medialab, with whom I had illuminating conversations on thinking about thinking and the impact of switching the properties of atoms and bites; and Wendy Feliz, from the American Immigration Center, who helped me understand the differences between my Latino immigrant experience and others’.

In Wudang, Master Gu Shining, head of the Wudang Daoist Wellness Center was so kind to show me the mountains, the routine of his school, and other local masters from his sacred mountains. Thank you for being such a great host and for so promptly answering my hundreds of online consultations after our days together. Yinyin’s Shifu’s school and the man himself are highly modeled after him and his center. Then in Shanghai, I had the pleasure of meeting Shifu Jiang Xinian who not only trained and lectured me in Wudang Tai Chi and answered dozens of silly and important questions, but also introduced me to his wife, Kong Lingna, with whom I had insightful conversations about Chinese feminism. Back in San Francisco, these interactions continued online and got reinforced by two local Wudang Masters: Sally Chang, Lindsey Wei.

Finally, my most important thank you goes to all my (long and short-term) instructors in the fighting arts—starting with Shifu Nilson Leão, Sensei Will Yturriaga and Coach Jordan Lutsky, for their years of dedication to my and my training partners’ journey. Then, to Mario Nicolau, from Porto Alegre, Brazil (Shao Shin Hao Kung Fu); John Khang, from Richmond, VA (Wing Chun); I Made Sandia and Ni Nyoman Sayun Trinadi from Bali, Indonesia (Silat); Nick Veitch, from Taiwan (Wing Chun); Marco Lee, from Beijing (Wing Chun and Chinese Boxing); Fabio Gurgel, Andre Rocha, and Pedro Henrique Barros from Rio de Janeiro, Brazil (Brazilian Jiu-Jitsu); from Penápolis, Brazil, Massao Shinkai (BJJ); from San Francisco, Kurt Osiander, Lucio Muramatsu, Victor Oliveira, Devan Green (BJJ) and Long Vo (Boxing); Rigan Machado and Lucas Leite, from Los Angeles (BJJ); from New York City, Eduardo Capeluto, Nima Sheini, Dan Covel and Jin Yung (BJJ), plus Simon Burgess and Gianna Smith-Cuello (Muay Thai); from Port Chester, NY, Rafael Formiga, Omar Delgado, Felipe Rocha, Fabio Canela, Nick Navarro, Jamie Nottingham, Jeff Nelson and Nick Arnel (BJJ), Teeik Silva (karate)—and all my classmates and students who always challenged me with the right mix of generosity, compassion, curiosity, and pain. If it wasn’t for you, the fight scenes in this book wouldn’t feel realistic. Therefore, I wouldn’t exist.