How far would you go to save your son? The fifth book in the best-selling time travel series, Tesseract continues the story of Josh and Caitlin and their desperate search for their missing son, Zachary. Taken beyond the borders of their continuum, they will need to recruit the greatest scientific minds of the twentieth century to create a powerful tesseract, a multi-dimensional portal that can unlock the alternate timelines of the Anunnaki. But what they find will question everything they know about the origins of humanity.