dazzled, tyler schultz became a believer.oined the company soon after getting his degree in biology from stanford. >> when you met her and heard about liz beth holmes vision what did you think? >> i was totally sold on it. >> reporter: tyler schultz began working at the company in september 2013. a pivotal moment, as the company announced a partnership with walgreen's. the deal would put an edison machine in every store. elizabeth holmes claimed the edison performed all of the tests big lab machines like these could. from cholesterol to cancer. all from a painless finger rick. but tyler schultz says the edison he saw just didn't work. >> was it a sophisticated piece of machinery? >> no. come components would fall off in testing. you had to fish out. doors that wouldn't close. they would get too hot. get too cold. >> when i was there we could not complete any test accurately on the devices that we were manufacturing. >> reporter: doug mechie joined theranos in 2012. his job was to adapt blood tests for the edison. tests which

you were talking to tyler schultz as a source. edcalled you. what happened then? >> my first original source wasn't tyler but he was an important corroborating source. i first made con account with him through linkedin. then one afternoon at "wall street journal"'s manhattan

you were talking to tyler schultz as a source. edcalled you. what happened then? my first original source wasn't tyler but he was an important corroborating source. i first made con account with him through linkedin. then one afternoon at "wall street journal"'s manhattan headquarters. he's terrified. he's got a burner phone. he starts telling me about his experience at the company which lasted 8 months and ended with him trying to raise his concerns with elizabeth and her boyfriend who was number two in the company. they basically told him in no uncertain terms that he was too young and too green and didn't know what he was talking about and told him to shut up or leave. so he ended up leaving. at which point elizabeth called his grandfather george, the famous former secretary of state and told him if tyler persisted in pursuing this vendetta against her, he would lose. howie: elizabeth wouldn't talk to you. but you met with her high-powered lawyer and it got hot. >> they came to our offices at the "wall street journal" in 2015. heather king who had been a partne