As Meredith and Cristina discuss their relationship woes at the Emerald City Bar, the bartender collapses.
When a family arrives at Seattle Grace Hospital after a serious car accident, Alex learns that their injuries are only the beginning of their problems.
Some family secrets become public when Meredith's mother, who has Alzheimer's disease, is brought to Seattle Grace for surgery; frightening news about Cristina's health comes into the open.
Cristina proves to be a difficult patient as she continues to recover; Meredith's mother keeps the hospital staff running in circles; Dr. Shepherd's involvement in the case of a cystic fibrosis patient could delay her departure.
Meredith and Dr. Shepherd have to use more than medicine when a young woman's traditionalist, religious father forbids her to have a life-saving operation.
A train crash brings several seriously injured patients to the hospital, providing a distraction for Meredith as she awaits Derek's final decision.
A male patient who seems to have a hysterical pregnancy fascinates the staff.
Derek and Addison's close friends come to Seattle Grace seeking radical surgery to avoid breast and ovarian cancer.
The Thanksgiving holiday is more difficult for the interns and residents than any of them is willing to admit.
A man comes to the hospital with priapism, and Meredith awkwardly realizes that he is her one-night stand.
Cristina Yang has little sympathy for an inmate (Rosanna Arquette), who jeopardizes her health to get out of solitary confinement.
Burke and Yang disagree on how to treat a young boy who does not seem to want a needed heart-transplant.
Izzie cannot ignore the chemistry she shares with a patient awaiting a heart transplant; George treats Bex, a teenage hermaphrodite.
Meredith and Cristina lie to each other about their relationships; George must discharge an elderly patient who is no longer sick but refuses to leave the hospital.
The nurses at Seattle Grace Hospital go on strike, leaving the doctors to fend for themselves; an elderly patient's friends (June Lockhart, Betty Garrett and Rae Allen) bring Meredith's mistake to light.
Meredith's premonition of having a bad day is realized when a medical case arrives threatening the lives of everyone in the OR.
Despite the best efforts of the Seattle Grace staff, the code-black situation escalates.
Someone from Derek and Addison's past arrives in Seattle; Burke learns Christina's secret; Meredith looks into her family's dirty laundry after a visit with her mother.
Meredith and George suddenly find themselves at odds at work; Bailey, although technically still on maternity leave, finds herself treating Addison for an unusual feminine issue.
It becomes a bad day for Christina when Bailey instructs her to take care of her baby; Derek and Addison come to terms with their relationship.
When a series of deaths occurs at Seattle Grace, the uncanny events bring out the doctors' superstitious sides and make Izzie nervous about Denny's surgery.
George begins to overstay his welcome; Meredith learns a secret about her father; Bailey gets back into a surgery room; Alex gets a lesson in bedside manners.
Izzie grills George about the personal details of his life; Addison takes Alex to task about a sensitive case, and Burke treats his musical hero.
The interns care for a family involved in a car accident; Derek lets his emotions get the better of him; Burke and Izzie have a new suggestion for Denny.
Finn offers a health update on Doc; Meredith must work with Callie for a day; George works with Derek; Burke and Izzie continue to search for a new heart for Denny.
Pressure to find a new heart for Denny increases; Callie confronts George about his feelings for her.