When "Grey's Anatomy" Season 12 begins, the ABC medical drama is returning to its roots, reports Variety.

The new season starts three months after the Season 11 finale, and romance will be in the air.

"We'll just say that we are giving new life to sexy over 50," Debbie Allen, who portrays Dr. Catherine Avery, told Variety, referring to her relationship with Dr. Richard Webber (James Pickens, Jr.). "We have a very hot relationship. Richard has got her busy."

According to a source close to the show, fans can expect the flirting, dating and sex in Season 12 that was common in the series' beginning when the doctors were sneaking off to the on-call rooms and Meredith Grey (Ellen Pompeo) and the late Derek Shepherd (Patrick Dempsey) met through a one-night stand.

"Grey's Anatomy" Season 12 kicks off with Alex Karev (Justin Chambers) and Jo Wilson (Camilla Luddington) living together in their new loft.

Owen Hunt (Kevin McKidd) and Amelia Shepherd (Caterina Scorsone) will decide if they are platonic friends or friends with benefits. A source with knowledge of the show told Variety the pair will be like a high school couple making out all the time.

Callie Torres (Sara Ramirez) and Arizona Robbins (Jessica Capshaw) are still split, but their friendship will evolve to a new level as both start dating other people.

April Kepner (Sarah Drew) and Jackson Avery (Jesse Williams) split up last season. April left town. When the new season begins, the couple will still be experiencing relationship problems. Fans will learn early-on in the season what will become of their relationship, according to Variety.

"When we left, my son, he was going through a little drama with his wife, and you know Catherine has a lot to say about that," Allen said on a laugh.

She added, "It's a story really about relationships -- friendships, betrayals, love, no love and all of that. It just happens to be in a hospital."

"Grey's Anatomy" Season 12 returns on Thursday, Sept. 24, at 8 p.m. ET on ABC.