Jamie-Lynn Sigler, Drop Dead Diva Jamie-Lynn Sigler, Drop Dead Diva

Sopranos alum Jamie-Lynn Sigler is back and better than ever — well, except that her Drop Dead Diva character is dying.

Fall Preview: Get scoop on your favorite returning shows

Sigler, whose recent credits include Ugly Betty and Entourage, will make her Diva debut in the Season 3 finale as Tina Howard, a travel agent whose adventure days are over.

"Jamie plays a terminally ill cardiac patient," creator Josh Berman tells TVGuide.com exclusively. "Her only chance of survival is getting a new heart. The only heart available to her is her brother's [Jonathan Schaech], who is on death row. But the prison system won't permit him to give her his heart, even after he's executed."

Lifetime renews Drop Dead Diva for fourth season

Even if she could get the heart, she doesn't want it since she thinks her brother is a terrible person for being convicted of killing a child. Suffice to say, Jane (Brooke Elliot) has her work cut out for her when she takes on Tina's case. Don't give up hope for Tina's survival though. Berman says, "We're already trying to figure out a way to bring her back." That shouldn't be too hard since the show was just renewed for a fourth season.

The season finale airs Sunday at 9/8c on Lifetime.