While recording sound waves across the universe, NASA makes an astonishing discovery close to home. A strange audio transmission is detected in a remote region of northern Brazil. The transmission has no known source, and the signature has only been recorded on two other occasions: once from inside the Andromeda Galaxy.Determined to discover if the sound was produced by alien intelligence, the US government turns to the Delphi Group. Senior Delphi operative Zane Watson is tapped to lead a select contingent of academics, locals, and US Army Special Forces deep into the heart of the Amazon rainforest, seeking to unlock the mystery of who or what is hidden there.Stalked by a shadowy group with their own agenda and facing terrors both ancient and modern, the team follows a trail of clues to a dark corner of the jungle, a place so horrifying that even the indigenous people fear crossing its borders.From a high-rise apartment building in Taiwan to the mountains of Idaho and the jungles of Brazil, the stakes for Delphi have never been higher.