4Marketing analyst Nick Vanderoff, newly retired from his successful career in business, lost his wife last year to cancer. Now he just wants to rest, relax, and repair family relationships. To accomplish this, he's been spending time with his math-genius granddaughter, Holly, and his estranged daughter. But a serial killer is on the loose in Dallas, and traditional forensics have produced nothing. Nick has consulted for the police department before, but not on anything like this. Can he trust the algorithms that worked so well in the corporate world to flush out a madman? The answer becomes personal when Nick's projections thwart the killer's plans, and he realizes the police are closing in on him. The sniper attacks escalate, and the killer turns toward Nick and his family. Will Nick be able to use his marketing skills to target a lethal segment of one to reveal himself?