Recent events strain Burke and Cristina's relationship. Mark and Derek must work together when two close-knit brothers seek medical help. One of Meredith's half sisters is admitted to the hospital.
Sociopath — Anya Marina
Mer, Alex, Christina, George, and Izzy eat in "really old guys room"; Meredith defends Christina against the others.
The twins are reunited after surgery. Susan tells Mere that they could be her family too. Mere tells the others to let Cristina off the hook. Cristina goes with Derek to examine Burke's shoulder.
The adult twins are separated. Mere updates Susan about Molly's baby, then tells her she's nice, but not her family. Hahn tells Cristina she reminds her of herself.