William Fichtner will star in a TNT pilot with Sherry Stringfield

We're not sure what the future holds for Agent Mahone on "Prison Break," but the actor who plays him has found another TV gig.

William Fichtner, who has played the twitchy lawman for the past four seasons on FOX, has signed on to star in a TNT pilot called "Night and Day." Former "ER" star Sherry Stringfield has also joined the show, which was co-created by "24's" Joel Surnow.

"William and Sherry have made audiences sit up and take notice time and time again with outstanding performances in a number of series and films," says Michael Wright, who heads up original programming for TNT and its sister networks. "We are proud to have them on board for this gritty and exciting series pilot."

"Night and Day" will center on Fichtner's character, an ATF agent who's part of a federal task force dealing with serious law-enforcement threats. The show will explore the balance he tries to keep between his work and his home life, where his wife (Stringfield) serves as the family's anchor.

Fichtner's commitment to "Prison Break" currently supersedes his role in the pilot, meaning that if both the show and Mahone survive into next season, TNT will have to recast the part.

His other credits include "The Dark Knight," "Invasion" and "Blades of Glory." Stringfield, a three-time Emmy nominee for her work on "ER," recurred on HBO's "Tell Me You Love Me" last season and has recently guested on "Shark" and "In Plain Sight."

Surnow wrote script and is executive producing with Todd Robinson ("Lonely Hearts," "White Squall").