"I will be joining Crisis this season," Byrne shared on Twitter before adding, "Have to pack!"
Crisis is described as a political thriller starring X-Files alum Gillian Anderson, Dermot Mulroney, Lance Gross, and Rachael Taylor. There's no word yet on who Byrne will be playing.
Crisis is scheduled as a mid-season series, meaning it likely will not air until early 2014. The show's official web site describes the series with a question no parent would want to have to answer. "How far would you go and what would you become to ensure your child's safe return?"
Byrne appeared as Lily on As the World Turns from April 1985 through April 2008. From 2000 to 2003 she also appeared as Rose D'Angelo. For a short time in 2009, Byrne played Andrea Floyd on General Hospital.
For more information, visit the show's official web site at nbc.com/crisis