Oprah Oprah

Oprah Winfrey promises to reveal a family secret when she hosts a family reunion on her show Monday.

The 56-year-old talk show host said that the reunion involves something she's learned about recently and is only known to a few people close to her.

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"I was given some news that literally shook me to my core. This time, I'm the one being reunited," she said in a promotional spot, calling it "the miracle of all miracles."

No further details were provided. Kitty Kelley's 2010 unauthorized biography of Winfrey claims that Vernon Winfrey isn't Winfrey's biological father. Kelley said she discovered the identity of Winfrey's actual father, but was keeping the name under wraps until Winfrey found out the truth herself.

Will you watch Monday?