There's a tree on the campus of the University of Hawaii in Manoa that tells a story of history hidden in plain sight.

You'd never tell by looking at it.

It's a rather unassuming tree as most trees go.

But then again, this story is about what's missing.

The tree itself was a thank you gift from the king of Thailand.

It was a symbolic gesture for an important medical breakthrough developed on campus,

a treatment for Hansen's disease, also known as leprosy.

The seeds of the tree were the solution.

Its oils held an active ingredient known to provide relief from the disease.

But the medical field lacked the knowledge to refine it for treatment.

That was, until a young black woman from Seattle figured it out.

Her name was Alice Ball.

The problem was the story.

Ball's name wasn't a part of it.

It was left off of her study, missing from history,

and nowhere around the tree planted in recognition of her work.

I'm Jerome Campbell, and this is Alice Obscura,

a celebration of the world's strange, incredible, and wondrous places.

Today, we're going to get down to the root of the matter,

the untold story of Alice Ball, the impact of her work, and how her story

became the true telling of history. I don't know about you, but I like to think of myself as someone who knows just a bit about science.

But my list of notable figures in the field generally consists of the usual suspects.

...