This is 99% invisible.

I'm Delaney Hall, filling in for Roman Mars.

In 1997, a curator named Catherine Ott

was learning her way around the Smithsonian National Museum

of American History.

She was new to the job.

She specialized in medical science.

And there was this one storage room

in the building where she worked.

It's like that classic, what you'd think of

as a dark, dusty, sort of scary, mildly, mysterious

storage room in a museum.

There were drug jars.

There was parts of mannequin bodies laying around.

But the weirdest thing was there was this wheelchair

that had go-cart wheels.

It was completely customized.

It had a recarrow seat that was used in Porsche cars.

But I kept tripping over it.

And finally, I'm like, what the heck is this thing?

So Catherine Ott started asking around,

where did this wheelchair come from?

...