There were numerous underlying stories in the final days (and second installment) of this terrific two-part episode, "Six Days."

Derek is still having trouble sleeping, which has transformed the ever-happy MerDer into a relationship with nagging and annoyances and nit-picking. In other words, the honeymoon phase appears to be over.

Along with dealing with a crabby boyfriend, Meredith is dealing with her ever-present father, who is still lurking about the hospital.

Meredith doesn't want to see any part of herself in Thatcher, but Cristina and Izzie gleefully point out her resemblance to him.

In fact, Meredith's medical career may be one of the only things she has in common with her mother. And maybe this glimpse into her father's life will catapult her into trying to build a relationship with him. She desperately needs a relationship with her father, even if he is a little bumbling and awkward.

Izzie donated money so a girl could walk upright, a gesture that proves to Bailey that she is still capable of forming attachments to her patients. However, in Izzie's eyes, this is not always a bad thing. In fact, her caring and compassion may prove to be what sets her apart from the other surgeons.

Addison is dealing with her abortion of Mark's baby eight months ago. She's sure Mark wasn't ready to be a dad, and she never wanted a baby with him at all. She wanted Derek, but now she fears she's ending up alone - which may be leading her into Alex's arms.

Alex and Addison are clearly feeling something for each other that neither one is sure he or she should feel. But how many interns can be dating attendings at once? Surely there's some kind of limit.

But the main story of the episode centers on George. His father's organs are failing and there's nothing left to do but hope. George's friends stand by him, hoping with him. But things aren't looking good.

Something clicks in George's mind and he realizes that the Chief and Bailey proceeded with the surgery because of his father's wishes. George breaks down, letting out all his built up emotions from the past few days in a heartbreaking scene in front of the whole hospital.

When George and his family decide to let his dad go, his friends are right outside waiting for him. We learn that Cristina lost her own dad when she was young, and so she can sympathize with George in a way that none of the others can.

Hopefully, the tragedy is over for George and he can start moving on, in the same way Izzie has. A lot of things are still left hanging, and we can only wonder what surprises are just around the corner.

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.