Betty White on Her 30 Rock Appearance: "Don't Blink!"

Keep your eyes peeled and don't take an ill-timed pee break during Thursday's 30 Rock because you may miss Betty White's guest spot. Well, it's more like a cameo.

"That's such a quick thing. It'll be over before you know it. Don't blink! It's one line. It's a line-and-a-half maybe," she tells TVGuide.com. "I think I'm yelling at poor [Tracy] Morgan."

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So why is White — who's playing herself — letting Tracy Jordan have it? "To tell you the truth, I don't even know the story line of the plot because I just went in, did the one line and left," she says. "I didn't even meet the cast — even the guy I'm yelling at was somebody else reading the line."

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Our Golden Girl may not know the plot, but we do: Tracy fears he may bite the dust after two celebrities die."I'm a great fan of the show," White says. "It's a wonderful show and it was fun just to be part of it for a minute."