Many thanks to my friends at Appian Way and Warner Bros. who supported the research and writing of this book, and to Leonardo DiCaprio, whose desire to tell an animal trafficking story set this whole journey in motion.

I am deeply grateful to my good friend Damien Mander, founder of the International Anti-Poaching Foundation. He took me to the front lines and beyond in South Africa and Mozambique. And to Sean Willmore (Thin Green Line Foundation) for helping me understand so much. The passion both these men have for protecting wildlife and rangers has been an inspiration throughout.

Huge thanks to Karl Ammann for taking me along on his undercover investigations in Southeast Asia and for connecting me with his local fixers, who must remain anonymous for security reasons.

Thanks to my agent Mel Berger, my editor Michael Carr, and the good folks at Blackstone Publishing for believing in this book.

Big salute to author Josh Conviser for all the encouragement and advice.

Warm thanks to all those who took the time to educate me: Dr. Jane Goodall, Dr. Matthew Frieman, Dr. Cindy Harper, Dr. Andrew Rassweiler, Crawford Allan, Peter Lodge, and Chris Shepherd. To the many officers from CIA, Homeland Security, and US Fish and Wildlife who helped me get it right, I can’t thank you enough. To all those I have left unnamed, please know that you are appreciated more than you can know.

Thank you to my mother, Dr. Lila Thorsen, for the notes and encouragement early in the process.

Finally, I owe my greatest debt of gratitude to my wife, Stacey, for all the support and for doing double-duty with our two young children while I was on the road researching this book.