Leap Breakthrough series, book 2

Summary: It was one of the greatest breakthroughs in human history. An achievement that stunned the entire world. And it was only the beginning. Facing the cold, clear glass, Alison Shaw stared nervously into the giant seawater tank. It was just one year ago that she and her team of marine biologists had stunned the world with their incredible breakthrough. And now, they were about to do it again. But an ocean away, something strange was unfolding. Along a lonely coast in South America, an experimental Russian submarine, long thought to have been dismantled, has suddenly resurfaced. And the U.S. Navy has taken notice, sending officers John Clay and Steve Caesare to investigate. The sub has been studying a group of unmarked soldiers. Disappearing into the jungle each night beneath the cover of darkness. Something has been discovered... something big. And it's about to fall into the wrong hands. Unless Alison Shaw and her team can find something that no one else can.