In New York, Denver, Paris and Berlin, four people have died separately in apparent accidents. Two women - the widows of two of the dead - find themselves under ruthless attack and are drawn together in fear and confusion, and for mutual protection. But are they being targeted because one of them is the prosecution witness at a famous criminal trial? Or is there a connection to the mystery behind their husband's deaths?
Thrown together, the women could not be more different: Dianne Stevens is a well-connected, affluent artist from the Upper East Side; Kelly Harris is an African-American model who, having grown up in a rough Philadelphia neighbourhood with a new 'uncle' every month, is now married to a brilliant scientist.
Meanwhile, Tanner Kingsley, chief executive of an international think-tank created only seven years ago, is on the cusp of an amazing discovery which could alter the future of the world. If properly handled, its outcome could deliver unbelievable power into the company's hands. But are the mysterious deaths connected to this volatile secret?