About nine years ago, 17.5 million people tuned into an episode of Grey’s Anatomy that, on the surface, appeared like any other — high-stakes surgery, high-drama love triangles. What those millions of Grey’s viewers didn’t know was that they were guinea pigs for a massive, secret experiment.

That experiment was arguably a referendum about a single woman: Jennifer Jako, and her decision to become a mother.

In 1991, at the age of 18, Jako had a one night stand with a high-school friend. It was the only time she’d ever had sex without a condom. She contracted HIV and spent years trying to debunk misconceptions: producing a documentary that aired on MTV, speaking at college campuses and on talk shows.

Over time, the country’s view of HIV evolved. As people started living longer, stigma decreased. People generally understood that the infection wasn’t a death sentence any longer.

But there was one area people couldn’t seem to understand: Pregnancy. Studies showed the general public simply didn’t know — or didn’t believe — that an HIV-positive woman, with the right treatment, had a tremendously low chance of passing the virus onto her baby — less than 2-percent at the time.

Jennifer Jako got a cruel lesson in where the public stood when she appeared on the cover of Newsweek magazine, six months pregnant.

Later, as an experiment, the Kaiser Family Foundation decided to see if they could move the needle by trying something totally different: product placement of medical information in a Grey’s Anatomy episode.

In this episode of Only Human we tell the epic story of Jennifer Jako and how she managed to sneak into our livings rooms and, possibly, change public opinion forever.