'Grey's Anatomy' season 13 spoilers, casting news: Amelia has important news for Owen in episode 5; 'Brothers & Sisters' alum lands mysterious guest role

Amelia (Caterina Scorsone) has important news to share with Owen (Kevin McKidd) in the upcoming episode of ABC's top-rating medical drama "Grey's Anatomy" season 13.

 Titled "Both Sides Now," this week's episode will explore yet another conflict in the Grey-Sloan Memorial Hospital. According to the official synopsis for episode 5, Meredith and Bailey will argue with each other when both of their patients need a liver transplant. Owen asks help from the other doctors after being tasked to babysit Harriet, April (Sarah Drew) and Jackson's (Jesse Williams) baby, for the entire day, while Amelia finds it difficult to tell some important news to Owen.

Meanwhile, the show is adding another member of the Shondaland extended family to its lineup. According to reports, actress Marika Dominczyk will be joining the series for a mysterious role. Details about the character she will portray, the number of episodes she'll participate in and her first appearance are still being kept under wraps.

Dominczyk is married to "Grey's Anatomy" alum and "Scandal" regular Scott Foley. She is known for her roles on "Brothers & Sisters," "The 40-Year-Old Virgin" and "Who Do You Love." She also joins a trio of actresses recently tapped to enter Grey-Sloan in a season where Arizona (Jessica Capshaw) will be getting a new love interest. Tessa Ferrer is reprising her role as Arizona's former girlfriend Leah, while Bridget Regan will be in the series for an unspecified role.

In an interview with Entertainment Weekly, executive producer Shonda Rhimes revealed that Arizona will be back to the dating scene this season. "We're absolutely going to see it," Rhimes said. "I'm very excited to introduce a love interest for her, and to get to tell a story with her that lets her be who she is, and to see who she is post the relationships that she's had."

The 13th episode of "Grey's Anatomy" airs every Thursday nights at 8 p.m. ET on ABC.