Episode number: 01
Original air date: September 27, 2007
Plot: Everything changes. As Meredith, Cristina, Izzie and Alex face their first day as residents while, having failed his exam, George is forced to relive his life as an intern. Callie struggles with the responsibility of being Cheif Resident while Bailey wrestles with her newfound freedom. Meredith tries to define her relationship with Derek as Cristina discovers that Burke resigned after leaving her at the altar. Izzie confronts George about their prolonged separation and Lexie, Meredith’s half-sister, begins her residency at Seattle Grace.
Episode number: 02
Original air date: October 4, 2007
Plot:Cristina panicks when Burke’s mother arrives at the hospital while the residents are put to task when the victims of an explosion at a apartment complex flood the E.R. George comes to a realization about the future of his marriage while Lexie makes her best efforts to have a presence in Meredith’s life. Callie begins to struggle with the pressures of being Cheif resident while, conversely, Bailey searches for ways to make herself useful.
Episode number: 03
Original air date: October 11, 2007
Plot:Cristina discovers that Meredith and Derek have rekindled their relationship prompting Meredith to question if she should keep things under wraps. A recently awoken coma patient has a few truths for the hospital staff, particularly Izzie who soon realizes the reality of her situation while George tries to come clean to Callie about the state of their marriage. Alex struggles with his new intern and Mark and Richard try a new, radical procedure.
Original air date: 05
Plot: Halloween dawns at Seattle Grace and Meredith begins to believe that her dead mother is haunting her and she and Richard both try to look for ways to put her to rest and reach closure about her death while Callie announces Izzie and George's affair to the entire hospital. Ava returns to see Alex who becomes conflicted by his desire to be with and his duties as a resident. Erica Hahn joins the staff of Seattle Grace, much to the dismay of Cristina.
Original air date: 06
Plot:Erica's first day at Seattle Grace pits Izzie and Cristina in direct competition for her attention and a place on the cardio service while George and Izzie finally find themselves free to be together but struggle to find time for eachother. Meredith must council a patient who miraculously survives a deadly free-fall and Mark helps Callie get back at George by involving him with two feuding patients. With his marriage is disaray, Richard turns to the men of Seattle Grace for help.
Episode number: 07
Original air date: November 8, 2007
Plot:George and Izzie's romantic chemistry is put to the test as they try anything to recreate the magic of their first time together while Callie turns tp Bailey when the pressures of being Chief Resident begin to build up. In the aftermath of her night with Alex, Meredith and Lexie bond over a patient who struggles to connect with his new adopted daughter resulting in Lexie telling Meredith her "five things" as Mark develops an interest in a reluctant Erica.
Episode number: 08
Original air date: November 15, 2007
Plot: An accident brings a busload of high school students to Seattle Grace and causes all of the doctors to relive their adolescense, most of all Bailey whose shared history with the bus driver causes her to relive her teenage anxiety while Callie deals with her demotion from Chief Resident. Cristina gets a chance to impress Erica while Derek begins to date other women. Their father's presence in the hospital causes conflict between Meredith and Lexie and George and Izzie balance their relationship and their friendship.
Episode number: 09
Original air date: November 22, 2007
Plot: An ambulance crash at the hospital leaves the lives of two paramedics hanging in the balance and the doctors work to save their lives as Meredith can't bring herself to tell Derek her true feelings. Bailey faces a moral crisis when she treats a white supermesist as her marriage begins to suffer under the pressure of her new role as Cheif Resident. Cristina strives to earn her place on the cardio service while Izzie is tested by Erica. Ava returns to see Alex, complicating his relationship with Lexie.
Episode number: 10
Original air date: December 6, 2007
Plot:Meredith and Richard work furiously to save the life of a paramedic trapped in an ambulance while Lexie holds the life of a patient in her hands. Derek must rely on Rose to save his patient after a technical fault interupts his surgery and threats his patients life. Izzie's commitment to cardio is questioned when she struggles to maintain patient care and Bailey's marriage takes a hit as she, George and Cristina work to save the life of a white supremacist.
Episode number: 11
Original air date: January 10, 2008
Plot:Bailey's family begins to fall apart as her marriage reaches breaking point but the situation is worsened when her son is rushed to the hospital after suffering life-threatening injuries. Derek questions what his kiss with Rose meant, and what impact it has on his future with Meredith, while Erica confronts Mark about his constant flirting. George must face the percurssions of his affair when his mother arrives in Seattle, unaware that he and Callie split, and the staff are all baffled by a patient who believes herself to be a faith healer.
Episode number: 12
Original air date: April 24, 2008
Plot: A surgical competition binds the residents to the hospital as they all desperately compete for points. Meredith, who has begun seeing the hospital therapist, struggles to avoid Derek and Rose's new relationship. while Izzie desperately works to win the competition and prove herself. Callie and Erica's friendship continues to grow, much to the surprise of Cristina, while George and Lexie face more than the usual challenges of living together when they move into their new apartment.
Episode number: 14
Original air date: May 8, 2008
Plot:Cristina has to face her feelings for Burke when news of his winning the Harper Avery reaches Seattle Grace while a "date-and-tell" policy is instated at Seattle Grace when the nurses protest against Mark's trysts. Erica feels put aside by Callie who begins to distances herself and prove her sexuality by sleeping with Mark. Izzie struggles to let Alex move forward with Ava after learning the truth about her pregnancy and Richard uses George to prove to Adele that he is delegating.
Episode number: 15
Original air date: May 15, 2008
Plot: The hospital buzzes over the arrival of Walter Tapley, a founding father of cardiothorastics and the former mentor of Richard whose unexpected request pushes the Cheif to encourage Erica to perform a risky procedure. Dr. Wyatt refuses to let Meredith quit therapy after a disagreement while Alex learns the truth about Ava's condition. Cristina struggles to escape her dark place and takes her anger out on Lexie and Callie tries to make sense of her newfound feelings for Erica as Mark tries to turn over a new leaf.
Episode number: 16
Original air date: May 22, 2008
Plot:Meredith strives to overcome her personal issues after making a breakthrough with Dr. Wyatt, as she faces her need to meet her mother's expectations of her, while she and Derek treat the final patients in their clinical trial. Cristina gets her surgery mojo back while Callie confronts her feelings while Izzie tries to support Alex as he cares for Rebecca, whose mental state begins to be questioned. Callie struggles to act on her feelings for Erica as Lexie learns suprising information about George's status as an intern. The surgerons band together to free a boy from a hardening block of cement.
Episode number: 17
Original air date: May 22, 2008
Plot:Meredith and Derek are given one last patient for the clinical trial and the conflict that arises between the two prompts a dramatic chance on their relationship as Meredith tries to come to terms with her mother's suicide attempt years previously. Izzie is tested as a doctor when Alex arrives at the hospital with Rebecca after she tries to kill herself. George struggles with knowing how close her came to success and Bailey tries to delegate to save her marriage. Callie takes a chance on her feelings while Erica's refusal to teach Cristina brings her into conflict with the Chief.