4.13 Piece Of My Heart
This episode starts with Derek telling Meredith not to get her hopes up, which strikes me as odd. Derek was always the hopeful one. Then, they come across Addison, who immediately hugs and assumes they're a "happy couple." Oh, boy.
"You broke up... with Meredith Grey? I hugged her! I hugged her!" Addison says angrily later to Derek. She has a point. The legacy or Meredith and Derek was something big, something epic, and even Addison says, "What are you doing?" Yeah, Derek. What ARE you doing? At the end, Addison says everything all of us MerDer shippers wanted to say. She tells Meredith not to let her get away, thank goodness.
Sadly, Meredith and Derek lose their first clinical trial patient. Little do they know... it's just the beginning.