After just seeing a fire and the departure of Dr. Stephanie Edwards (Jerrika Hinton) in the 13th season finale of “Grey’s Anatomy,” Grey Sloan Memorial is about to see even more changes when the 14th season of ABC’s benchmark medical drama premieres.

Not only will a character previously presumed dead return, but there are also multiple love triangles further complicating the work environment of Seattle’s favorite doctors.

It’s bound to be a roller coaster ride of a season, so to prepare for the two-hour, back-to-back episodes “Break Down the House” and “Get Off on the Pain” that make up ABC’s premiere event, Variety broke down several key things to know about Season 14 of “Grey’s Anatomy.”

Megan’s return shakes everything up:

Megan Hunt (now played by Abigail Spencer) returning after a decade of being missing and presumed dead will affect all of the major players. Riggs (Martin Henderson) won’t know how to act, Owen (Kevin McKidd) is wracked with guilt about not continuing to look for his sister and Meredith (Ellen Pompeo) is dead-set on being the hero for Megan, despite their shared connection to Riggs.

Love triangle No. 1:

Riggs doesn’t want to tell Megan about Meredith, but both Teddy (Kim Raver) and Maggie (Kelly McCreary) will talk some sense into him about having enough respect for Megan to be honest with her, which sets up a solid love triangle for our beloved Meredith Grey. Of course, nothing is ever that simple on “Grey’s” – and this time it’s all complicated by the fact that Megan has some serious medical issues to deal with.

Love triangle No. 2:

Much like the end of last season, things are still very strained between Amelia (Caterina Scorsone) and Owen. She, of course, wants to be there for him in the wake of his sister being found alive, but that event doesn’t erase the problems in their “sham of a marriage.” Plus, Teddy is back and she and Owen have just as much chemistry as they ever did. Amelia and Teddy will meet in the season premiere, and though it’s not long, it’s awkward.

Love triangle No. 3:

Jackson (Jesse Williams) and April (Sarah Drew) will have to deal with the fallout from their hook-up in Montana. And as if that doesn’t come with its own awkwardness, what April said in the Season 13 finale about Maggie and Jackson having feelings for each other still looms. A confrontation is coming, which could cause further complications – or the beginning of a beautiful new relationship.

It’s not all drama all the time:

Since the tradition of “Grey’s” is to mix business with pleasure, of course there will be a couple of hook-ups in the premiere, including one for Arizona (Jessica Capshaw). While these characters never seem to learn that it would help to keep their personal and professional lives separate, or at least outside of the hospital’s walls, they provide some fodder for lighter moments that could keep the comedy infused all season.

A search for Jo’s new BFF:

In the wake of Stephanie’s departure from the hospital, Jo (Camilla Luddington) needs a new BFF. Interestingly, she is going to enlist Ben (Jason George) in that role. Ben will do his best to help her with her feelings for Alex (Justin Chambers) for now, but she may need another new candidate soon, as he will be leaving “Grey’s” for its firefighter-centric spinoff.

“Grey’s Anatomy” Season 14 premieres at 8 p.m. on Sept. 28 on ABC.