Bloodline is the eighth Sigma Force novel from James Rollins, published in 2012. The premise is one of the more ambitious in the long series, weaving together the kidnapping of a high profile American family member with cutting edge research into human longevity and the kind of historical mystery that the wider Sigma Force universe has been building across multiple books. The daughter of the President of the United States, Amanda Gant Bennett, has been kidnapped from a yacht off the coast of Somalia, and the investigation pulls Sigma Force into the kind of international intrigue that combines diplomatic complications, military action, and the deeper scientific and historical mysteries that drive the larger series.
The science element of the novel involves real research on the genetic basis of human aging and on the potential for biological interventions that could extend human lifespan substantially beyond the current biological limits. The antagonists have been pursuing this research for their own purposes, and the kidnapping of Amanda turns out to be connected to their larger project in ways that the Sigma Force team has to work through across the page count. Rollins draws on actual research in the longevity science field, citing his sources at the end of the book as he typically does, with the speculation reaching beyond the current state of the art while remaining grounded in plausible directions that the science could potentially develop.
The plot moves through Somalia, Egypt, Italy, and the United States in the globe trotting structure Rollins’s readers expect. Painter Crowe coordinates from headquarters. The field team handles the active leads, with Gray Pierce and Seichan leading the action sequences while Kowalski provides the kind of supporting muscle that the various dangerous situations require. The recurring antagonist organization called the Guild, which has been one of the major running threads across the wider Sigma Force series, plays a significant role in the wider conspiracy that the novel slowly uncovers.
What distinguishes Bloodline from some of the other Sigma Force novels is the high political stakes. The daughter of a sitting president has been taken, the diplomatic and military complications of any direct American intervention are significant, and the wider implications for the Sigma Force team and for the larger American political situation give the novel real weight beyond just the procedural thriller plot.
For longtime Sigma Force fans, Bloodline is one of the stronger middle period entries.