ABC/Mitch Haaseth

There's nothing like a family reunion on Grey's Anatomy.

Traditionally, families reuniting in any way hasn't gone well on the ABC drama as new family members are almost always there to cause trouble, pain, or at least throw a wrench into somebody's plans, and by the look on Amelia's face in these exclusive new pics, her reunion with two of her sisters is going go to be one of those painful, troublesome ones.

Amy Acker will make her debut in the Thursday, April 11 episode as Kathleen Shepherd, the one Shepherd sister (of four) that we haven't yet met. In the episode, Amelia (Caterina Scorsone) and Link (Chris Carmack) head to New York to operate on a patient with a severe spinal deformity, and they end up invited to dinner at the home of Nancy Shepherd, along with Kathleen.

Embeth Davidtz is returning as Nancy Shepherd, the OB/GYN we first met in season three when she showed up unexpectedly to visit her brother Derek, and really enjoyed calling Meredith "the slutty intern."