Dr. Michael Sterling suffers from extreme social anxiety which he combats by using a Dot. A symbiotic robot that he controls from his Condo in Sacramento, California. Due to the unrest of the non-gifted side of humanity he is forced to step out from behind his beloved Dot and into the real world.
This change begins the destruction of his career, with him not being able to function in public without his anxiety showing. His last chance to save himself and his career; cancer research, but what he finds is so much more.
When found he sees the soul for what it is, a part of the body, like the heart or lungs, and learns that cancer is hiding on the skin of the soul, so he builds Soultracer to map and block cancer from returning to the body. Effectively curing cancer after it is put into a remissive state.
Fame, wealth, and fortune follow, but in a society that is plagued with overpopulation, starvation, homelessness, did he do society a favor? Or prolong the suffering of humanity.
His answer, Soulbraider.
Being gifted like her father, several years later Dr. Sue Sterling works as a champion of the Soulbraider project to "braid" the souls of the dying to the souls of the living to preserve a soul line. What she finds is that the secret purpose of Soulbraider.
Her father explains how he proved the soul moves forward from person to person and that it isn't generated at birth, Soulbraiding is creating miscarriages and still births in the future thus reducing population.
At first horrified, but eventually brought to the understanding that this is the most humane way to slow the birthrate, she goes along with the plan. Fully consumed with guilt and curiosity, she conducts her own monstrous experiments where she finds that her father is wrong.
Souls move backward in time, not forward.
Rebuilding Soulbraider to attach to the soul to the one body part it never attached to, the mind, Sue sets in motion her first step into following her soul into the past so she can try to fix overpopulation before it begins.
Her two twin teenagers find out about what has happened and end up destroying Sue's version of the Soulbraider, but not before they are both are braided and forever entangled to the fate of the Souls passage backward.