John Gearhart's lab is closed to outsiders.

Rather than happening there, an interview brokered by a university public affairs officer takes place in a windowless lecture room in the bowels of the Johns Hopkins University School of Medicine. Outside, seedy east Baltimore vibrates with the energy of a bright spring day. Gearhart appears and takes a seat under the fluorescent lights. Time is short, and no tape recorders, please.

With reddish blond hair and a direct gaze, Gearhart speaks with excitement about the vast medical potential of the research going on in his lab. He describes the early stages of human life and an elusive cell found only in embryos. But there's much about this conversation that's fleeting, incomplete and evasive. Suddenly his voice turns defiant and he's scowling deeply. He relates how he and his family have received threats, how other scientists have criticized his failure to publish and his close ties with industry. And then he is gone, sprung by the clock-conscious PR man.