From the New York Times –bestselling author, a companion volume to the popular History Channel series.

A young girl digs up a thousand-year-old humanoid skull from a cave in northern Mexico. But the skull contains no human DNA.

An amateur videographer taking footage of lights over Mount Shasta, California, captures a giant floating triangle on tape. It's not a plane. It's not a helicopter. What is it?

These questions and more are answered in UFO Hunters Book Two. Using eyewitness accounts and information from footage never before seen on television, author William Birnes takes readers on the hunt for the real truth about flying saucers, what they are, and why they're here.