Holmes' former protégé, Kitty Winter, warns him of a killer who is eliminating everyone involved with a case they worked on together in London. Watson discovers that Kitty has a life changing secret.
Addison clashes with Sam's new girlfriend, Vanessa, over treatment for a patient whose life, and those of her unborn triplets, hangs in the balance.
Violet files for joint custody of Lucas, but Pete hires an attorney and fights back, dragging everyone at the practice into the trial.
The doctors venture into controversial territory when an unexpected new hire at Pacific Wellcare causes Naomi to struggle with the idea of genetically designing babies. Meanwhile, Violet decides to try electric shock therapy on a patient.
Addison, Amelia and Fife try to save Maya and her unborn child, Sam makes a grim discovery and Cooper makes a valiant effort with Charlotte. Later, an unexpected death leaves everyone stunned.
