"Grey's Anatomy" creator-executive producer Shonda Rhimes pens the special two-hour episode titled "The Other Side of This Life," which airs at 9 PM. The episode will repeat May 4 at 8 PM. (All times ET. Check your local listings.)
"Addison takes temporary leave from Seattle Grace and makes a road trip to Los Angeles in order to visit some old friends from medical school," an ABC summary reveals.
The possible spinoff features Diggs (Rent) and Daly (The Caine Mutiny Court-Marshall) as well as Paul Adelstein ("Prison Break"), Amy Brenneman ("Judging Amy"), Merrin Dungey ("Alias") and Chris Lowell ("Veronica Mars").
They join "Grey's Anatomy" regulars Sandra Oh (Satellites), Chandra Wilson (Caroline, or Change), T.R. Knight (Noises Off) and Sara Ramirez (Monty Python's Spamalot) as well as Ellen Pompeo, Patrick Dempsey, Isaiah Washington, Katherine Heigl, Justin Chambers, James Pickens, Jr. and Eric Dane. Diahann Carroll and Elizabeth Reaser also guest star.
Diggs last appeared Off-Broadway in A Soldier's Play. He lent his dulcet tones to the hit movie musical "Chicago," the film "Rent" and TV's "Will & Grace." The actor seen onstage in Carousel, The Wild Party and Chicago is perhaps best known for originating the role of Benjamin Coffin III in the musical Rent — where he met his wife Idina Menzel. Diggs has appeared in the films "How Stella Got Her Groove Back," "Go" and "The Best Man" as well as on television in "Ally McBeal," "Ed" and the title role in "Kevin Hill." Walsh is also a veteran of the stage. The San Jose, CA, native became involved in regional theatre while attending University of Arizona. She then headed to Chicago and worked with the Piven Theatre Workshop and the Chicago Shakespeare Repertory, appearing in Born Guilty, Moon Under Miami and Troilus and Cressida. In New York City she performed onstage with the comedy troupe "Burn Manhattan" and in the Off-Broadway plays Flight Courier and The Four Twins.
For more information, visit ABC.com.