With Meredith taken aback after meeting the doctor who could not save her husband, Derek, in the concluding scene of last week's ‘Grey's Anatomy,’ this time it’s all about Ellen Pompeo’s character struggling to entertain the doctor as a guest in her dinner party.

In the new trailer, viewers can have a glimpse of the immediate result of Callie's (Sara Ramirez) introduction of new girlfriend Penny (Samantha Sloyan), which strongly involves Meredith’s recall of unpleasant memories.

Sloyan first appeared in the episode in which Derek (Patrick Dempsey) was involved in an ultimately fatal car accident. The actress took on the role of a young doctor at the Dillard Medical Center who, despite her attempts, eventually failed in saving his life.

She had an unforgettable conversation with Meredith, saying that Derek's face is what she is going to remember every time she treats a patient. Meredith pointed out that such experience would either make Sloyan's character better in her field or would make her quit in the end.

Showrunner Shonda Rhimes previously revealed that both Callie and Arizona would have new love interests in the latest installment.

"That felt natural and it's what the story is about and how it plays out. I really tried to stay true to the idea that she's bisexual but it's literally what the story is,” Rhimes said.

Ramirez also opened up about her character’s storyline, saying: "She's exploring new love and it's a hot dating situation and there's some unexpected twists and turns as always. They do it brilliantly and it's in a way that affects a lot of people."

Despite Dempsey’s exit, the critically acclaimed series has already shared its first few episodes with renewed energy and enthusiasm.

When asked about her experience of having to say goodbye to her co-star, Pompeo admitted that they all miss him but are focusing on transforming such energy into a productive opportunity.

“Any time we lose a member of the cast, you feel it. The energy shifts,” she shared. “But in order to create great drama, we need big things to happen. And every time a beloved cast member has left, it gives us new air.”

The mother-of-two also explained how much her character in the hit AMC drama is in need of such changes, saying that these new experiences are necessary for everyone to stay inspired.

“We're looking for things to not stay the same,” she added. “They have to stay the same to some extent but you welcome change because that's what inspires the writers, that's what inspires the actors.”

'Grey's Anatomy' season 12 airs Thursdays at 8 p.m. ET on ABC.