'Grey's Anatomy' season 13 news, spoilers: S13 will kick off with 'explosive' drama; could Owen's sister be alive?

"Grey's Anatomy" season 13 will start off with a bang, actress Caterina Scorsone, who plays Amelia, has said. The upcoming season will also reportedly put the spotlight on the long-running medical drama's original core characters and could reveal that Owen's (Kevin McKidd) sister is alive.

In a recent interview with The Hollywood Reporter, Scorsone shared that season 13 will pick up immediately after the events in the season 12 finale, i.e. after Amelia and Owen's wedding.

"Immediately on the tail of Amelia and Owen's wedding, there's a big explosive drama that's happening right away," she told the outlet. According to the "Grey's Anatomy" star, while a literal explosion is indeed possible in the catastrophe-ridden world of "Grey's," season 13 will instead be "emotionally explosive."

"It's going to be a key story this year that a lot of people are going to be interested in," Scorsone added.

While the actress clarified that this "explosive" drama will have nothing to do with Amelia and Owen, fans have been speculating that the upcoming season of "Grey's Anatomy" could see the emergence of Owen's missing and long-thought-dead sister, who also happened to be Riggs' (Martin Henderson) fiancée. After all, "Grey's Anatomy" is no stranger to surprise sibling reveals, as in the case of Maggie (Kelly McCreary) and Lexie (Chyler Leigh).

In an interview with Entertainment Weekly, "Grey's Anatomy" creator Shonda Rhimes hedged around the possibility of Owen's sister turning up, saying, "As for whether or not the sister is dead, I think that's interesting people think that's a question, but that's an interesting question."

Meanwhile, Scorsone also revealed that "Grey's Anatomy" season 13 will focus on the remaining original characters, namely Meredith (Ellen Pompeo), Bailey (Chandra Wilson), Alex (Justin Chambers), and Richard (James Pickens, Jr.).

"There is going to be a lot of checking in with the original cast," she said.

Speaking with TV Guide earlier this month, McCreary said that one of the things she is looking forward to most in season 13 is "the focus on ... those old, established relationships and those characters."

"Grey's Anatomy" season 13 premieres on Thursday, Sept. 22, at 9 p.m. EDT on ABC.