Amelia (Caterina Scorsone) will lash out at Meredith (Ellen Pompeo) for letting the person partially responsible for Derek's (Patrick Dempsey) death work under her service in the upcoming episode of the ABC's hit series "Grey's Anatomy."

In "The Me Nobody Knows," the synopsis reveals that the sisters will not see eye to eye regarding the new resident in the hospital, who turns out to be Callie's (Sara Ramirez) new girlfriend. Penny (Samantha Sloyan) was introduced to the gang last episode during Meredith and her siblings' dinner party. Callie, for her part, was horrified to learn that Penny was somehow connected to Derek's death. The others were shocked as well, especially once they learned that Penny was transferring to Grey Sloan Memorial Hospital.

According to the preview released by ABC, Amelia is furious that Meredith will take in Penny under her wing. She does not know that Meredith has no choice about it, as Bailey (Chandra Wilson) is the one responsible for the set up. At first, Meredith looks like throwing up, just thinking about having the woman who let Derek's life slip away under her watch. She will soon get over it, though, and appreciates what Bailey is trying to do for her.

She will tell Amelia that she is trying to rise above the situation, which she should do as well. But her sister is already blinded with rage. She is seen shouting at Meredith that she should have forced Penny to transfer to another hospital during their dinner party and not let things go that far. Her pleadings, however, will fall on deaf ears, as Penny can be seen doing her shift with the other residents.

When she and Amelia meet in the hallway, the latter gives her the cold shoulder. Will Amelia see sense and accept that Penny is there to stay? Meanwhile, Penny is also getting snubbed by her other colleagues. In the promo, her joke about the pastor who is having his head examined will be met with silence.

"Grey's Anatomy" airs Thursday nights at 8 p.m. EST on ABC.