Izzie copes with the loss of Denny and her decision to leave the internship program; Meredith faces decisions about her future after her liaison with Derek.
Cristina meets Burke's parents; the interns campaign for Izzie's reinstatement; Addison takes a break from her hospital duties; a surgical patient lives what may be her last day to the fullest.
Cristina helps Preston cope with his hand tremor; Izzie returns to the hospital for the first time since she quit the program.
Addison doubts her abilities; Cristina pushes Burke's rehabilitation; an intern suffers a medical emergency.
Bailey treats a young mother battling breast cancer; Derek learns more about Mark and Addison's relationship; the interns defend a resident's competence at a staff meeting.
Cristina draws the envy of the other doctors when she scrubs in for the "humpty dumpty" procedure; George and Addison work with a pregnant woman who faces an unusual dilemma.
The men of Seattle Grace go on a camping trip; Addison and Callie must team up to work on a patient; Meredith assists with a procedure Sloan has never experienced; Bailey confronts Cristina, suspicious of her recent actions.
The O'Malley family visits George at the hospital; Meredith determines to have a more positive outlook on life; Derek and Addison strive for a civil relationship; Richard endeavors to reunite with his wife, Adele.
A traumatic car accident fills the ER; Cristina has a crisis of conscience about her deceptive teamwork with Burke; Izzie pushes the boundaries of probation.
Recent events strain Burke and Cristina's relationship; Meredith's half sister enters the hospital; Mark and Derek must work together when two close-knit brothers seek medical help.
George's father has surgery for his cancer; Thatcher Grey arrives to see his new granddaughter; Meredith finds that Derek has trouble sleeping.
Mark is furious with Addison; George's father continues to recover after his surgery.
Bailey proposes the creation of a free clinic; a Seattle Grace doctor receives a proposal.
The doctors compete for Richard's affections; a surgical patient endangers the lives of those around her; Meredith's mother, who has Alzheimer's disease, experiences a change in her medical condition.
A ferryboat accident on triage-training day tests the interns.
Meredith's friends and fellow doctors work to save her life after her near-drowning; Izzie gathers her courage to perform surgery at the site of the ferry accident.
Meredith flatlines and gets a visit from Denny and Dylan (Kyle Chandler) in the afterlife; Derek and Meredith's friends work together to bring her back from the brink.
The race for chief heats up as a new competitor comes forward; Callie must reveal a big secret; Derek treats a patient close to him; Alex continues his work with Jane Doe.
George meets his new father-in-law; Alex helps Jane Doe determine how the world will see her; the hospital board begins interviewing candidates for the chief position; Izzie wrestles with a startling revelation.
Izzie faces her past and finds comfort in George; Alex has an attachment to Jane Doe; Meredith and Derek question their status; Cristina resolves to fight for her relationship with Burke.
The attendings are extra-attentive to a patient, who is the chairman of the hospital board; Cristina helps Burke plan the wedding.
Addison takes a temporary leave from Seattle Grace and visits old friends in Los Angeles; Cristina reluctantly plans her wedding with help from Burke's mother (Diahann Carroll) and her own; Derek must perform surgery on Jane Doe.
Addison takes a temporary leave from Seattle Grace and visits old friends in Los Angeles; Cristina reluctantly plans her wedding with help from Burke's mother (Diahann Carroll) and her own; Derek must perform surgery on Jane Doe.
The interns take their first-year medical exams; the residents attend to three injured mountain-climbers; Callie's suspicions of George and Izzie grow; Cristina struggles to write her wedding vows.
Cristina and Burke's wedding day arrives; the interns get their exam results; the chief's successor; Callie and George make a decision about their relationship.