Cell

Cell is an unnervingly plausible medical thriller from the master of the genre, Robin Cook. George Wilson, M. D., a radiology resident in Los Angeles, is about to enter a profession on the brink of an enormous paradigm shift, foreshadowing a vastly different role for doctors everywhere. A new smartphone app, iDoc, is being developed that is far more than a mere reference tool, rather it is a fully customizable personal physician capable of diagnosing and treating patients more efficiently than the real thing.
George's initial collision with this incredible innovation is devastating. He awakens one morning to find his fiancée dead in bed alongside him, not long after she participated in an iDoc beta test. Then several of his patients die after undergoing imaging procedures. All of them had been part of the same beta test. Is it possible that iDoc is being subverted by hackers - and that the US government is involved in a cover-up? Despite threats to both his career and his freedom, George relentlessly seeks the truth, knowing that if he's right, the consequences could be lethal.