Meredith Grey has been teased to fall in love once again in the upcoming season of Grey’s Anatomy however it seems that there is someone who will block her way to happiness.

The 13th season of the ABC medical drama is set to premiere on September 22 and it will pick where season 12 conclude – Meredith (Ellen Pompeo) and Dr. Nathan Riggs (Martin Henderson) sleeping together.

At the end of Grey’s Anatomy season 12,  Amelia (Caterina Scorsone) and Owen (Kevin McKidd) also got married while a romance is blooming between Meredith and Nathan.

When the two doctors tied the knot, most of their colleagues and friends attended the ceremony, including Riggs. It looks like Nathan’s attendance was the first step toward reconciliation with Owen.

Nathan’s arrival at the wedding was a surprise for Grey’s Anatomy fans since there has been hostility between Owen and Riggs since the latter join the Grey Sloane Memorial Hospital this season.

Where does the resentment between the two doctors coming from?

Nathan was Owen’s late sister husband. Owen always blamed him for not being able to save his sister. Owen is now married to Derek’s sister, Amelia. Meredith is Derek’s widow. Owen and Derek (Patrick Dempsey) were friend. To add to the all these twists, Meredith half-sister Maggie (Kelly McCreary) seems to be eyeing Nathan as well.

Meredith and Nathan have decided to keep their relationship a secret. However, it will be revealed eventually next season and McKidd said his character will not like it at all.

“I don’t think Owen is going to be happy about that. He’s almost becoming an unofficial brother to Meredith. Derek was his friend. He’ll be a bit territorial, to be honest,” he told Entertainment Weekly.

Henderson earlier revealed in a separate interview with Entertainment Weekly that things are looking better between Owen and Nathan in the 13th season. The actor said the relationship between the two doctors is going to be healed until Nathan will do something stupid.

Grey’s Anatomy returns on Sept. 22 at 8 p.m. ET on ABC.