Will fans mourn the death of one of "Nashville's" important characters when the show returns for season 4? 

Fans of the highly acclaimed drama were left with a big question at the end of the third season finale, when a heart monitor flatlined while Deacon (Charles Esten) and his sister Beverly (Dana Wheeler-Nicholson) were in the middle of the liver transplant procedure to treat his cancer. No one knows who got the flatline or if both the siblings managed to survive the surgery. 

But "Nashville" executive producer Dee Johnson's interview with TV Guide teased that whatever happened during the season 3 finale will have a great effect on the events that will happen in season 4.

"Nothing is going to be the same, obviously, after we come back," Johnson shared.

According to the executive producer, Deacon's one great love Rayna (Connie Britton) will have a difficult time adjusting to the changes happening in her personal and professional life.

"Certainly from a personal point of view, but also from a business point of view, because in addition to the cliff-hanger that we had, a lot of stuff changed in Rayna's business world too," Johnson stated. "She comes into this new world order having to kind of start from scratch again on a lot of levels." 

This could mean that the Highway 65 music label executive was deeply affected by Deacon's health, and her record label might be having problems in the coming season. 

Meanwhile, Juliette (Hayden Panettiere) still seems to be battling her post-partum depression, and it will affect her relationship with her husband Avery (Jonathan Jackson). In a separate interview with TVLine, Johnson said that the couple still has a lot of things to overcome during the first few episodes of the season.

Also in the premiere episode of "Nashville" season 4 titled "Can't Let Go," Aerosmith's front man Steven Tyler will make a guest appearance during one of Juliette's concerts. According to reports, the rock star will perform Patsy Cline's single "Crazy" during the episode.

"Nashville" season 4 premieres tonight, 10 p.m. on ABC.  Catch it online via live stream on ABC.com