03/21/2012 09:11 am ET

'The Good Wife': Martha Plimpton Returns For Season Finale And More Casting News

Martha Plimpton is laying down the law one more time. According to TVLine, the "Rasing Hope" star will be back for the Season 3 finale of "The Good Wife."

Plimpton is returning to the legal drama as high-powered lawyer Patti Nyholm, who teams up with Michael J. Fox's character Louis Canning to take on Alicia Florrick (Julianna Margulies)'s firm.

In other casting news...

"SVU" star Stephanie Marchhas been cast in new CBS drama. March has nabbed the part of Natalie in CBS' legal drama pilot "Baby Big Shot." Labeled "Spence-educated Manhattan royalty," March will play a law associate who hopes to be head of the firm. [EW]

"ER's" Eric La Salle will appear in the "Widow Detective" pilot.
La Salle is set to guest star in the CBS pilot as a friend to John Corbett's character, with the potential of a recurring role if the series is picked up. [THR]

Jason O'Mara will co-star in a new period drama. The "Terra Nova" alum has landed a key role in the still-untitled CBS drama about the life of cowboy and sheriff Ralph Lamb. [TVLine]

"Smallville" actor Alan Ritchson joins the "Super Fun Night" pilot.
On "Super Fun Night," which revolves around a group of friends who are perpetually chasing "super fun" Friday nights, the actor will play hunky boyfriend to nerdy character Kimmie's younger sister, who is described as a hotter version of Kimmie. [THR]

Tom Lennon will guest star on the season finale of "New Girl." The "Reno 911" actor will appear on the finale as a potential new roommate for Jess (Zooey Deschanel) and the rest of the "New Girl" gang on the freshman Fox hit comedy. [THR]