An unlikely partnership develops between Li and Campbell as they follow the resulting lead. A fiery and volatile chemistry ignites: exposing not only their individual demons, but an even greater evil - a conspiracy that threatens their lives, as well as those of millions of others.

The polarity that once attracted Yan and Campbell eventually pulls them back into partnership. Yet the closer they are drawn to the truth, the nearer they come to a killer prepared to use extreme force to conceal it.

Li, Campbell and Mei Ling are now entering the arena of a sickening nemesis, and opening a door behind which lies each of their very worst nightmares.

Li and Campbell will soon find that the crime scene hides another secret: a biological time bomb linking traffickers, politicians and migrants in Beijing, Washington and Texas - posing multiple countries one, very singular, threat.

When Campbell's contact herself vanishes, the gun is fired on a race against time. And Li must now outrun, and outwit, an enemy bent on pushing him beyond endurance.

There's no way Li can misinterpret the Ripper's motives: he wants to tear Li and Campbell's lives apart, and write the darkest chapter in Beijing's history