Liquid fear

When Roland Doyle wakes up in an unfamiliar motel room with a strange man's wallet in his pocket and a woman's dead body in the bathroom, he fears the worst. That's before he finds the vial of pills labeled 'take one every 4 hrs or else.' Or else what? Ten years ago, Dr. Sebastian Briggs's clinical drug trial for a cutting-edge fear-response drug went horribly wrong, or did it?