Jeff Vespa / WireImage 1 / 5
Jeff Vespa / WireImage 1 / 5

By Dana Flax

Peggy Olson has hit the big time!

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According to TV Guide, Elisabeth Moss of "Mad Men" has been tapped for a guest role on NBC's new nurse drama "Mercy."

Playing Lucy Morton, a cancer patient who has lost her hair from treatment, Moss will don a scarf to mask her baldness.

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If her character takes any cues from the newly gay-made-over Peggy, it'll probably be one fabulous scarf.

"Mercy" airs on NBC at 8 p.m. on Wednesdays. Moss' episode will air on Nov. 4.

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