Thursday's episode of ABC's medical drama "Grey's Anatomy" will see Grey Sloan Memorial Hospital welcoming a new resident, who is going to make things even more awkward for Meredith and Amelia.

Penny, the doctor who was attending to Derek the day he died, will be a new transfer to the hospital, and she will be put on Meredith's service.

While Meredith initially tries to rise above the situation and work with Penny, a sneak peek of the upcoming episode shows Meredith finally losing her control and kicking Penny off her service.

Will this affect Meredith's relationship with Callie? Spoilers indicate that Meredith will confront her friend about dating someone who was indirectly responsible for Derek's death.

And this will put Callie in a precarious position, as she is yet to figure out her relationship with Penny.

"Well first of all you have to get Callie to just figure out what's happening between her and Penny," executive producer Debbie Allen told The Hollywood Reporter. "At the end of the episode, Callie doesn't even give her the address to where she is. Callie doesn't know how to react. Callie feels that maybe Penny should have told her more."

Things are also going to get more complicated between Meredith and her sister-in-law Amelia, and the latter is not going to be happy that Meredith is letting Penny work at Grey Sloan.

The official synopsis for the episode reads:

Grey Sloan Memorial not only welcomes a new transfer resident, but also a patient who's the topic of conversation after accidentally sending his sex tape to his entire congregation. Meanwhile, Richard wrestles with how to progress his relationship with Maggie when an old friend visits the hospital, and April brings in a case of a young boy from the Middle-East.

"Grey's Anatomy" is aired Thursdays on ABC. Click here to watch the episode online. The episode can also be watched online by clicking here