The arrival of Nathan Riggs has shaken up Grey Sloan Memorial Hospital. In the winter finale of "Grey's Anatomy" season 12, it was revealed that for some reason, Martin Henderson's character has something to do with the family of Owen, who was revealed to have a sister.

In an interview with The Hollywood Reporter, Kevin McKidd, who plays Owen, teased where his beef with the new guy is coming from. "[Nathan and Owen's sister] were definitely romantically involved and something happened — something Owen can't forgive or reconcile in himself," the actor revealed.

It is unclear what will take place next with Owen and Nathan in "Grey's Anatomy" season 12 and unfortunately, fans won't know until the show returns in February. From how things have panned out so for, it sounds like there will be a lot going on with Nathan in the show.

Just recently, Henderson had a sit-down interview with TV Line, where he emphasized that his character is by no means a replacement to Patrick Dempsey's Derek Shepherd aka McDreamy but can still be a substitute in Meredith's heart.

"Obviously it's a possibility," the actor said when asked about a potential romance with the widow. He added that due to the nature of the long-running drama, "It's just as viable that I end up with anyone on the show."

Henderson then vowed that wherever his character takes him, he will just do what he came to do – serve the audience and series creator Shonda Rhimes. "If [a Nathan-Meredith romance] happens, I know there would be some strong feelings, positive and negative," he recognized.

The actor also noted that it was fun working with Meredith's essayer Ellen Pompeo and Henderson knows that the elevator scene they shared together in the "Grey's Anatomy" season 12 midseason finale sort of showed how romance could indeed develop and how sparks are already flying around.

Nonetheless, Henderson leaves his character's fate in love and life in the hands of Rhimes, saying "If she feels there's something to be mined there she will. And if there's not then she won't."

"Grey's Anatomy" season 12 returns Feb. 11.