Antiques Roadshow has been running for over 40 years.

Thousands of episodes. Tens of thousands of appraisals.

And every so often, someone walks in with something that changes everything.

This is one of those stories.

It's 2012. A college-bound student is packing for school. She's inherited a framed picture from her grandmother, which has been hanging over her grandma's bed for years.

Sentimental. Not valuable. But there's a problem.

A mosquito. Trapped under the glass. She takes the picture outside. Opens the frame. Gets rid of the mosquito.

And then she pauses.

Wait. Is this actually a painting? Or just a print?

She's not sure. So she gets it appraised. First appraiser: $200.

Okay. Not bad. She gets a second opinion.

Second appraiser: $250. Close enough. At least it's worth something.

She almost doesn't bring it to Antiques Roadshow. Two appraisals. Both around $200. That's probably right.

But her mom nudges her. "We're already here. Might as well."

So she does.

The appraiser, Meredith Hilferty, takes one look.

Studies the brushwork. The detail. The signature.

The painting, circa 1892, was done by Henry Francois Farny, a French-born American painter known for his portraits of Native Americans.

Meredith looks up.

"Auction value: $200,000 to $300,000."