SEASONS

Owen and Richard compete for an extremely difficult surgery; Bailey gets ready for another date with Ben.

A famous surgeon is rushed to the hospital; Callie and Arizona try to help Teddy and Sloan move on from their pasts.

Callie, Bailey and Richard present pivotal surgical cases from their pasts when Derek restores the hospital lecture series.

The doctors treat dozens of people when the roof of a romantic restaurant collapses on Valentine's Day; Meredith struggles with her new duties as the chief's wife.

Derek faces a lawsuit on his first day as interim chief when a patient awakens from anesthesia during surgery; Mark refuses to speak to Lexie.

After learning about Richard's drinking problem, Derek confronts him; Izzie returns, hoping to reconcile with Alex; tensions run high for Teddy, Cristina and Owen in the aftermath...

Addison returns to Seattle to perform a procedure on Mark's pregnant daughter; Cristina is assigned the lead on a complicated surgery.

As the holiday season passes, Miranda is visited by her father, who disapproves of her life choices; Mark and Lexie must cope with the arrival of a woman from his past; Thatcher...

Owen recruits a fellow Iraq War veteran to be the new cardiothoracic surgeon, but Cristina questions the new surgeon's abilities; Izzie returns with her high school mentor seeking...

The parents of Arizona's 10-year-old patient offer the hospital a generous donation, but Arizona finds herself in a conflict of interest when the patient's condition worsens;...

When the hospital lab tech, Isaac, discovers he has an inoperable tumor wrapped around his spine, he turns to Derek for help; Derek challenges Richard's authority.

When a burn victim unexpectedly dies in the E.R., all the Mercy West and Seattle Grace residents must defend their actions in hopes of saving their jobs.

The residents of Seattle Grace and Mercy West vie for their careers as the hospital merger begins; Arizona stands by enraged Callie when Callie's father employs a priest to...

When Thatcher returns to the hospital with a failed liver, Meredith must save his life; Izzie empathizes with a tumor-riddled patient; annoyed with Cristina's competitive zeal,...

Izzie returns to work; Seattle Grace residents position themselves to avoid layoffs; Cristina tries to work with Arizona in the pediatric ward.

Members of the hospital staff find unique ways to deal with their grief at George's death; George's mother faces the daunting task of deciding what to do with his organs.

George delivers stunning news to Bailey, sending shockwaves throughout the hospital, and Izzie's friends anxiously await her recovery from surgery.

Izzie spends time with a fellow cancer patient and contemplates whether or not to undergo a risky surgery and George makes a big decision of his own.

Derek and Meredith get ready for their wedding; college students injured in a car accident are admitted to the ER; Izzie starts experiencing familiar symptoms.

Izzie gets a surprise visit from her mother (Sharon Lawrence); Thatcher tries to make amends with Meredith and Lexie; Meredith and the Chief argue over a controversial case....

As she endures aggressive treatment for her cancer, Izzie throws herself into planning Derek and Meredith's wedding.

Some of Izzie's friends fail to rally around her as Derek must overcome his fears in time to remove her deadly brain tumor.

Derek refuses to return to SGH and it takes a visit from the Chief himself to set him straight; Izzie's cancer secret comes out.

After learning at a deposition that more of his patients have died than survived, Derek decides to quit, even as Meredith refuses to give up on him.

Derek's confidence is shaken like never before as he faces off with Addison over what course is best for their dying pregnant patient.

Addison, Naomi and Sam rush the ailing Archer to Seattle Grace and reunite with old friends Derek and Mark to help save his life.

Now that Derek has the engagement ring, he searches for the perfect way to propose to Meredith, as Lexie demands that she and Mark go public.

Bailey grows desperate as a patient's condition becomes more and more dire.

Derek's mother makes a surprise visit to Seattle and meets Meredith for the first time, as Mark tries to conceal his relationship with Lexie from her.

Bailey teams with Seattle Grace's new pediatric surgeon, Dr. Arizona Robbins, to save the life of a young patient.

Cristina is awarded the first solo surgery among the residents, but must give it up and choose her replacement.

Meredith, Cristina and Bailey come to Lexie and Sadie's rescue when a surgery goes horribly wrong.

One of Meredith's oldest friends, Sadie, becomes an intern at Seattle Grace, but Mer's friends are less-than-welcoming to her.

The Chief announces to the residents that a solo surgery will be awarded, and the news sends them into a competitive frenzy.

To help Bailey become a better surgeon, the Chief gives her new power, new responsibility, and the challenge of removing a girl's inoperable tumor.

Bailey heads up a team of surgeons performing a "domino procedure" in which each surgery hinges on the one preceding it.

Meredith freaks out when Derek discovers her mother's old diary in the house and Cristina stumbles into a part of the hospital that she's never seen before.

A plumbing leak becomes a deluge and wreaks havoc at Seattle Grace, as the Chief attempts to implement new teaching policies.

Cristina's treated by Major Hunt after being impaled by an icicle and Meredith and Derek finally reach a conclusion about moving in together.

Meredith and Derek learn that "happily ever after" isn't easy, and a military doctor who brings in a trauma patient catches Cristina's eye.

Meredith and Derek have one last shot at a successful outcome in their clinical trial, as the other surgeons work to free a boy from a block of cement.

Dr. Wyatt refuses to let Meredith give up, Alex learns about Rebecca's condition and the Chief insists that Erica operate on his mentor.

The nurses' objections to McSteamy's trysts lead to the instating of a new "date and tell" policy.

Addison returns to Seattle Grace to perform an operation and is taken aback by all of the changes in her old co-workers' lives.

Meredith and her fellow residents compete in a surgical contest. Meanwhile George and Lexie adjust to their new apartment.

Bailey's family faces a medical trauma, just as her marriage is falling apart; a surprise visit from George's mother comes as a shock.

Meredith furiously works to save the life of a paramedic trapped inside an ambulance, as her sister, Lexie, holds the life of a patient in her hands.

An ambulance crash endangers the lives of the paramedics involved, as Meredith and the Chief work on-site to save them.

The ER is filled with teenagers after a schoolbus crash, Bailey treats a patient who was her high school crush.

George and Izzie's romantic chemistry is put to the test, Mark develops a crush on a fellow surgeon, and Callie's role as Chief Resident is in jeopardy.

With his marriage in trouble, the Chief turns to his fellow male surgeons for a "Gentleman's Evening," while Cristina and Izzie compete for surgeries.

Halloween is full of surprises as Meredith thinks her dead mother is haunting her and Callie reveals Goerge and Izzie's affair.

Izzie confides in a friend about George and the reaction is not what she expected; the Chief's niece returns to the hospital where she once had her prom.

Meredith reluctantly helps Lexie with her first surgical procedure, while Lexie helps keep George's "repeater" status a secret from their fellow interns.

Mama Burke returns to Seattle Grace, and Cristina does her best to evade her, while Meredith tries to avoid a heart-to-heart with Lexie.

Having just returned from her honeymoon with Meredith, Cristina searches for Burke, but he's nowhere to be found.

Cristina and Burke's wedding day arrives—along with the interns' first exam results—and a successor to the Chief is named.

The interns take the biggest test of their careers, their first year medical exams, as the residents attend to three injured mountain climbers.

Addison takes temporary leave from Seattle Grace and makes a road trip to Los Angeles in order to visit some old friends from medical school.

As the interns of Seattle Grace cram for their upcoming exam, the attendings vie for the Chief's position by tending to the chairman of the hospital board.

Izzie faces her past and finds comfort in George, while Alex becomes more attached to Jane Doe.

Izzie is reeling from the realization that she and George slept together, but George doesn't remember anything. All he knows is that he has a killer hangover...

The race for chief heats up after a new competitor enters the fray, tensions escalate between Izzie and George, and Callie must reveal a big secret.

Meredith's fight to live affects everyone at Seattle Grace.

Derek rescues a drowning Meredith, but was he in time to save the woman he loves?

The interns of Seattle Grace are challenged like never before when they go to the scene of a terrible ferry boat crash.

The race for the Chief's position is on, as the doctors compete for Richard's affections, a surgical patient endangers the lives of those around her.

While rumors of the Chief's departure spread among the hospital staff, Bailey proposes the creation of a free clinic.

After a successful operation on his heart, George's father undergoes surgery for his cancer.

After a successful operation on his heart, George's father undergoes surgery for his cancer, Thatcher Grey visits Seattle Grace.

Recent events strain Burke and Cristina's relationship, Meredith's half sister, Molly, is admitted to the hospital, and Mark and Derek must work together.

A traumatic car accident fills the ER, Cristina has a crisis of conscience about her teamwork with Burke, and Izzie pushes the boundaries.

The O'Malley Family visits George at the hospital, Meredith is determined to have a more positive outlook on life and Richard tries to reunite with Adele.

The men of Seattle Grace go on a camping trip together, Addison and Callie must team up to work on a patient, and Bailey confronts Cristina.

Cristina scrubs in on the rare 'humpty dumpty' procedure, much to the envy of her fellow doctors and Alex questions his future medical specialty.

Bailey treats a young mother battling breast cancer, Derek learns more about Mark and Addison's relationship and the interns defend a resident's competence.

Addison doubts her abilities as a doctor, Cristina pushes Burke's rehabilitation and one of the interns suffers their own medical emergency.

Cristina tries to help Preston cope with his hand tremor, Izzie attempts to return to the hospital for the first time since she quit the program.

Cristina meets Burke's parents in the most awkward of circumstances and the interns campaign for Izzie's reinstatement.

The doctors of Seattle Grace help Izzie cope with the loss Denny, and her decision to quit the internship program.

Derek and Richard finish Burke's surgery as Denny successfully undergoes his heart transplant, but it's not all 'happily ever after'...

Burke has been shot and Izzie has just cut Denny's LVAD wire. George, Meredith, and Cristina all wind up helping Izzie keep Denny alive.

A shooting at a nearby restaurant bombards the hospital with plenty of gunshot victims—and one intended victim that didn't get shot.

Derek is mad at Meredith, George is living back in the house, though still not talking to Meredith and Cristina begins the day on a rush.

Derek and Addison aren't having the best sex, something Meredith learns of by accident, just before Finn asks her out.

George begins to overstay his welcome at Burke's apartment, Meredith learns a secret about her father and Alex gets a lesson in bedside manners.

After four deaths in the morning, every doctors' personal superstitions and rituals come into focus.

It becomes a bad day for Cristina when Bailey instructs her to take care of her baby.

No one knows what transpired between George and Meredith but George and Meredith—and they aren't talking.

Meredith and Burke treat a patient who probably won't survive surgery and the patient asks Meredith to videotape him venting.

Despite the best efforts of the Seattle Grace staff, the code black situation escalates.

Meredith's fears that she is in for a bad day are realized when a medical case arrives at SGH that threatens the lives of everyone in the O.R.

The nurses at Seattle Grace Hospital go on strike, leaving the doctors to fend for themselves.

Meredith is calling Derek "McDreamy" again as he helps her get her mother in a special clinical trial.

Izzie seems to be getting over Alex when she shares an undeniable chemistry with Denny Duquette, a patient who's awaiting a heart transplant.

A boy needs a heart transplant but doesn't want it, and an argument over his treatment exposes philosophical differences between Burke and Cristina.

Cristina has little sympathy for Constance Ferguson, a prison inmate who jeopardizes her health just to get out of solitary confinement.

Meredith‘s one night stand has an erection that just won’t quit, Izzie catches Alex in the act with Olivia and Cristina gets keyed by Burke.

Happy Thanksgiving! Izzie has high hopes for a big family-style dinner while McDreamy and Addison schedule holiday sex and George’s dad takes a bullet in the behind.

McDreamy and Addison clash over their friend’s request for radical surgery while Meredith’s elderly patients restore her belief in true love.

Gossip is all the rage at Seattle Grace with Meredith feeling the brunt of it as a pregnant man comes into SGH and a heart spontaneously combusts!

A massive train crash causes two victims to be impaled on the same pole. Izzie chooses between friendship and advancing her career.

A power failure cripples Seattle Grace Hospital forcing George to operate in an elevator.

There’s hope for Meredith and McDreamy now that Addison gives him divorce papers to sign and Alex and Izzie go on their first date.

Secrets are out at Seattle Grace. Everybody finds out about Meredith’s mom when she comes in as a patient.

McDreamy wants to get back with Meredith. Addison wants to get back with McDreamy. Meredith just wants to keep it professional—with both of them.

Meredith is trying to process the fact that McDreamy is McMarried and Cristina is trying to deal with the fact that she's pregnant.

It's a syphilis outbreak at Seattle Grace as all of that sleeping around finally catches up with a few of the interns.

Alex gets Burke in over his head while Izzie reveals some issues with her mom and a psychic visits Seattle Grace.

George and Izzie find out about Mer and McDreamy while Cristina faces a test she's not quite prepared for.

A woman with a 70-pound tumor comes to SGH and Izzie is forced to perform her first solo surgery.

Meredith is overwhelmed causing her to make a mistake during surgery that could jeopardize her career.

Cristina clashes with a nurse as Meredith tries her best to figure out the rules of relationships.

Meredith Grey has discovered that the rules of residency are the same as the rules of life. Everything is a competition.

Meredith tries to figure out her relationship with Derek as George and Izzie move in with her.

Meredith Grey, Cristina Yang, Izzie Stevens and George O'Malley face their first day as interns at Seattle Grace Hospital.