Halloween is officially upon us on Grey's Anatomy. You can imagine the surprises destined to fall into the hands of the surgeons at Seattle Grace on this wacky holiday. Alex receives an unexpected visit from his former patient, while Meredith is convinced that her mother Ellis' ashes are haunting her, Cristina is snubbed by a surgeon she admires in Dr. Hahn, and Callie makes an announcement to her fellow doctors.
As the episode begins, Cristina is looking to rent out Burkeâ€™s apartment. She offers it to the Chief, who's officially been served with the divorce wishes from Adele. He accepts. Meredith for some reason decides that putting her momâ€™s ashes in a freezer bag and bringing them to work is a good idea. Izzie asks Callie a question and Callie tells her - and everyone else in the room - to please direct inquiries to Dr. Bailey as since Izzie is sleeping with her husband.
This episode promises not to disappoint.
Norman asks if he can go home because he's feeling under the weather. Alex doesn't care, and then learns that Ava - yes, Ava - is back.
She and Alex kiss in the on-call room. She reminds him he chickened out at the time she asked him for a reason to stay, but she's back because she wants to be with him. They have sex and fall asleep. Alex gets paged and tells Ava he'll be back so they can talk more about their situation.
He doesn't come back for a long time, though, because Norman had a stroke. When he finally comes back, Ava is gone. Alex apologizes to Norman for not answering his pages and for mocking him when he felt sick. Norman is going to switch his specialty to psychiatry, which is what he was leaning towards anyway, as surgeons are immature children. Which they are. But where's Ava? Will she return again?
Lexie Grey is wearing scrubs and a Little Bo Peep bonnet to work, in honor of Halloween, and gets criticized by the daughter of a patient who needs a heart transplant for not looking professional. The daughter is also wearing a costume - a mouse â€” but she doesn't cut people open for a living.
The daughter leaves, but is brought back later by paramedics when she is slammed by a brick. Really. She's still alive, but in a vegetative state. She's also an organ donor, with a heart her father could really use. Her father has the power to take her off of life support and have her organs donated... to himself, but he can't bring himself to.
George then makes a nice speech about how he's sure the daughter would have wanted him to take her heart because that's what he would have done with his own father. This convinces the man to take the transplant.
Richard invites Dr. Erica Hahn of Mercy West to perform the transplant, and Izzie and Cristina compete to be in on the surgery. Dr. Hahn picks Izzie because she calls Cristina out on her propensity to sleep with mentors.
This obviously doesn't go well with Yang, and she has it out with Izzie in the hallway. Cristina rips Izzie for sleeping with another woman's husband, and says that sleeping with Dr. Burke, who was her boyfriend and fiancÃ©, was completely different. Izzie fires back that Cristina and Meredith are a closed circle, always excluding and judging her - and wasn't Derek married when he and Meredith first started sleeping together?
Miranda has a patient named James who claims his foot that doesn't belong to him. That's a new one. He says it feels like a corpse's, and wants her to amputate. When she suggests anti-anxiety medication, James who steals the chainsaw used for the pumpkin carving contest and tries to cut it off himself. You've gotta love Halloween.
Callie and Cristina do the amputation surgery - now necessary as the man has mangled his foot - and laugh at each other's relationship woes. Later, Cristina tells Dr. Hahn off, saying that she didn't sleep her way to the top and that it's Hahn who is being unprofessional.
That's when Richard announces that Eric Hahn is going to be joining Seattle Grace as the new head of cardiothoracic surgery. She's staying around! A flustered Cristina responds by immediately taking her apartment back from Richard. She gives it to Callie instead! Roommates!
Meredith crashes into Derek in the hallway, spilling some of her "bag of mommy" on the floor. Derek says she is trying to deal and evolve.
A young boy, the son of a cafeteria worker, comes to ask for Mark, who is embroiled in his own problems right now as the nurses find out he's used the same lines to sleep with them all. They have unofficially formed a support group in Nurses United Against Mark Sloan. The kid, Ryan, is there to ask Mark for ears. He can hear but has no external ear structure.
Mark wants to help but won't do pro bono work. Meredith offers to use her mother and what's left of her "capital" to help convince others to help. She succeeds and lines everything up. Mark tells her that even though her mother didn't take the time to take her trick-or-treating when she was a child, Meredith Grey still turned out alright. It's sweet.
Meredith, Cristina and ashes of Ellis are eating lunch as George and Izzie sit down to join. They confirm that they are together and in love, but they are waiting to be "together" out of respect for Callie. Cristina rolls her eyes with disgust at this, but Meredith tries to remain on even keel.
Later, Miranda is on the phone with her husband, apologizing for missing their son's first Halloween. Tucker hangs up on her. George joins her and apologizes for disappointing Bailey with his adultery, but she tells him he's not a bad person even though what he did was unkind and hurtful and wrong. She says that it takes two to reach that point.
After their surgeries, Lexie tells Meredith that she buried her mom's cat next to her because she thought Susan would have liked that. Meredith is just happy to have a friend at this moment and says thank you. Mer has a plan now. She washes the ashes down the sink in the scrub area outside of the OR. Richard joins her, and Ellis Grey is finally laid to rest in an appropriate manner for such an accomplished surgeon.