"Okay." "Okay." "Okay."

The voices are robot feminine and they never shut up, each chirp a surreal announcement that another new iPad is about to be born.

"Okay." "Okay." "Okay."

The factory floor is spotless under the bright fluorescent lights and with hypnotic rhythm, thousands of hands reach into a conveyor belt river, bringing each gliding gadget to life one tiny piece at a time.

"Okay." "Okay."

A supervisor will bark the occasional order in Mandarin, but on this line the machines do most of the talking while the people work in silence.

Their faces are blank as they insert a chip or wipe a screen or plug in a diagnostic cable to hear that everything is "Okay."

And they will repeat that motion and hear that fembot voice a few thousand more times before lunch.

It is just an average day at Foxconn.

How 'Nightline' Got Inside Apple's Chinese Factories

Given the legendary secrecy of the world's most valuable company, you have to wonder: How am I seeing this? Well, a few years ago, I sent THIS to Steve Jobs, blatantly stealing the Apple beat from a more able colleague. I still feel guilty, but I don't regret it because I was genuinely taken with the second coming of Jobs and was unabashedly fond of Apple's products. My hope for a sweeping profile led to my covering a few launches and every six months we pitched them an ABC News special on the inner workings of Apple. They always politely declined.

But in recent months, the fond memorials for Steve Jobs and the company's record-breaking profits have been tarnished by some of the worst press in Apple's history, most of it related to its top Chinese supplier, Foxconn.

Just after a horrific rash of worker suicides at the Foxconn factory complex outside of Hong Kong in 2010, a monologist named Mike Daisey launched a one-man show called "The Agony and The Ecstasy of Steve Jobs." He described travelling to the gates of Foxconn and meeting people coming off 13-15 hour shifts on the Apple lines. He described a 13-year-old who spent her days cleaning iPhone screens.

PHOTOS: Inside Apple's Factories in China

Daisey's show was featured on NPR's "This American Life" in January and a listener named Mark Shields was so moved, he launched a petition drive online. Over 250,000 Apple users called on the company to build the first "ethical" iPhone, and protests were planned at Apple stores around the world.

It was around this time when Apple called me. They wondered if "Nightline" was interested in seeing their iPhone, iPad and MacBook final assembly lines at Foxconn during a first-ever audit by the Fair Labor Association. I said yes, very much, and immediately started imaging the reasons why they were offering such a scoop to me, of all people. Among the possibilities:

-I've said nice things about their products on the air.

-ABC News is owned by the Disney Corporation and Disney CEO Bob Iger serves on the Apple Board of Directors

-The Steve Jobs Trust is Disney's largest shareholder.

-They enjoy "Nightline."

It must be the last one, because the first three would have no bearing on my reporting and I'm pretty sure Apple knows it.

Watch "Nightline" anchor Bill Weir's exclusive full report on a special edition of "Nightline," "iFactory: Inside Apple."

'I Think About Resting'

Apple promised complete access, no dog-and-pony, no Potemkin Village, but they denied my repeated requests to interview Apple CEO Tim Cook or the senior vice president of industrial design, Jony Ive.

In a three-golf-cart convoy, both Apple and Foxconn reps took us around to a half dozen production lines in Shenzhen and Chengdu, and there were always five to six people with us as we toured the factories and dorms. But aside from suggesting a visit to the counseling center or canteen, they never steered us to interviews and never interrupted.

This is some of what we saw. See it yourself on Tuesday's "Nightline."

The pristine white boxes that roll off these lines in Shenzhen, China all carry the words "designed in California." But the collective genius of Cupertino would be nothing without the relentless, repetitive work of hundreds of thousands of Chinese and Taiwanese workers like Liang Juan.

Covered head to toe in a dust-free "bunny suit," the 26-year-old has spent most of the past three years flipping tiny camera lenses with a pair of tweezers.

"What do you think about all day?" I wonder. "I don't think much about other things," she says, "because the