<P> Renee Scolaro Rathke of PopMatters, reviewing the premiere, gave a mixed review, "Unfortunately, the best bits of the premiere were the flashbacks to the finale, though their impact was watered down considerably in the context of an action-less storyline, filled with Grey's usual rambling pontifications ." Verne Gay of Newsday was rather critical of the season stating, "Unfortunately, they've settled on far - too - easy and facile answers for the most part ." </P> <P> The number in the "No. in series" column refers to the episode's number within the overall series, whereas the number in the "No. in season" column refers to the episode's number within this particular season . "U.S. viewers in millions" refers to the number of Americans in millions who watched the episodes live . The seventh season's episodes are altogether 946 minutes in length . </P> <Table> <Tr> <Th> No . overall </Th> <Th> No. in season </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original air date </Th> <Th> U.S. viewers (millions) </Th> </Tr> <Tr> <Th> 127 </Th> <Td> </Td> <Td> "With You I'm Born Again" </Td> <Td> Rob Corn </Td> <Td> Krista Vernoff </Td> <Td> September 23, 2010 (2010 - 09 - 23) </Td> <Td> 14.32 </Td> </Tr> <Tr> <Td_colspan="7"> A trauma counselor, Dr. Perkins, tries to help the hospital staff in the recovery and to assess each doctor's readiness to return to work . Cristina and Owen plan their wedding, while Meredith fails to get approved for surgery . Derek quickly returns to work with adrenaline but worries Meredith when he continuously speeds while driving . </Td> </Tr> <Tr> <Th> 128 </Th> <Td> </Td> <Td> "Shock to the System" </Td> <Td> Tom Verica </Td> <Td> William Harper </Td> <Td> September 30, 2010 (2010 - 09 - 30) </Td> <Td> 12.53 </Td> </Tr> <Tr> <Td_colspan="7"> Meredith at last tells Derek about her miscarriage and is finally cleared to return to her surgical duties in the wake of the hospital shooting spree . Cristina experiences PTSD in the midst of an operation; and Bailey refuses to let Alex operate until he agrees to have the bullet in his chest removed . Several people are admitted to the ER after being struck by lightning . </Td> </Tr> <Tr> <Th> 129 </Th> <Td> </Td> <Td> "Superfreak" </Td> <Td> Michael Pressman </Td> <Td> Mark Wilding </Td> <Td> October 7, 2010 (2010 - 10 - 07) </Td> <Td> 12.75 </Td> </Tr> <Tr> <Td_colspan="7"> Derek's sister, Amelia, shows up at the hospital, and things go awry between the siblings; the Chief tries to help Alex with his trauma of elevators; Meredith and Derek try to help Cristina with her post-traumatic stress . </Td> </Tr> <Tr> <Th> 130 </Th> <Td> </Td> <Td> "Can't Fight Biology" </Td> <Td> Edward Ornelas </Td> <Td> Peter Nowalk </Td> <Td> October 14, 2010 (2010 - 10 - 14) </Td> <Td> 12.11 </Td> </Tr> <Tr> <Td_colspan="7"> Meredith and Derek receive some disturbing news from the obstetrician, and Lexie loses it when she notices Meredith and April getting closer . Meanwhile a car crash brings in multiple traumas and Jackson tries using his physical attributes to get ahead in the operating room, while Cristina's self - doubt carries outside of the hospital and into her house hunting with Owen . </Td> </Tr> <Tr> <Th> 131 </Th> <Td> 5 </Td> <Td> "Almost Grown" </Td> <Td> Chandra Wilson </Td> <Td> Brian Tanen </Td> <Td> October 21, 2010 (2010 - 10 - 21) </Td> <Td> 10.97 </Td> </Tr> <Tr> <Td_colspan="7"> The Chief puts the residents in charge while the attending surgeons compete for a million - dollar grant, and Callie tries to psych everyone out . Derek tells the Chief of his wish to start a clinical trial for Alzheimer's . </Td> </Tr> <Tr> <Th> 132 </Th> <Td> 6 </Td> <Td> "These Arms of Mine" </Td> <Td> Stephen Cragg </Td> <Td> Stacy McKee </Td> <Td> October 28, 2010 (2010 - 10 - 28) </Td> <Td> 10.79 </Td> </Tr> <Tr> <Td_colspan="7"> A documentary film crew visits the hospital six months after the shooting to document the recovery process of doctors and patients . Mary Portman returns to the hospital to have Bailey perform her surgery . Meanwhile, Derek and other surgeons prepare to do a double arm transplant on a logger who lost his arms in an accident four years previously . Alex treats a young girl who is slowly dying that no other doctor has been able to cure up to now . Alex, however, looks for an alternative cure . Derek is able to operate and save the logger . In the end, Alex manages to find a treatment that involves the growth of a trachea in vitro and saves the life of the girl . After Arizona receives an elite medical grant based on a proposed project in Africa, she and Callie decide to go together . Although the surgery went well, Mary does not wakeup and Bailey is devastated . </Td> </Tr> <Tr> <Th> 133 </Th> <Td> 7 </Td> <Td> "That's Me Trying" </Td> <Td> Tony Phelan </Td> <Td> Austin Guzman </Td> <Td> November 4, 2010 (2010 - 11 - 04) </Td> <Td> 11.92 </Td> </Tr> <Tr> <Td_colspan="7"> Cristina is left alone to watch an ill patient while Teddy goes to retrieve his organ transplant . Owen puts the residents through a rigorous trauma certification drill . Mark and Lexie perform surgery on a woman who wants butt implants . Callie and Arizona prepare for their trip to Africa, but at the airport, Arizona says she does not want Callie to go, as she has been so ambivalent . Callie ends the relationship . Bailey tries to deal with the trauma of losing Mary . </Td> </Tr> <Tr> <Th> 134 </Th> <Td> 8 </Td> <Td> "Something's Gotta Give" </Td> <Td> Jeannot Szwarc </Td> <Td> William Harper </Td> <Td> November 11, 2010 (2010 - 11 - 11) </Td> <Td> 11.13 </Td> </Tr> <Tr> <Td_colspan="7"> Cristina tries to decorate her house for a housewarming party while the hospital welcomes a new Pediatrics Attending, Dr. Robert Stark . Alex receives a verbal beatdown from Stark . When April stands up for Alex, it leads to them getting intimate . Being a virgin, April asks Alex to take it slow, but the conversation leads to Alex getting agitated as it starts to remind him of his experience with previous women . April bursts into tears at Cristina's housewarming party . When Jackson learns about what happened to April, he starts punching Alex out of rage . Meanwhile, Derek advises Sloan and others to not have an intervention for Cristina . Speaking from experience, he says it isn't a good idea . No one can seem to find Cristina at her own party; she is on the terrace, having drinks and a conversation with Derek about tiles . </Td> </Tr> <Tr> <Th> 135 </Th> <Td> 9 </Td> <Td> "Slow Night, So Long" </Td> <Td> Rob Bailey </Td> <Td> Zoanne Clack </Td> <Td> November 18, 2010 (2010 - 11 - 18) </Td> <Td> 11.46 </Td> </Tr> <Tr> <Td_colspan="7"> The residents are on their own when they have to take a night - shift, and realize things go very differently at night . The attendings head to Joe's to celebrate Derek's grant for his clinical trial and are shocked when they see that Christina has started work as a waitress there . </Td> </Tr> <Tr> <Th> 136 </Th> <Td> 10 </Td> <Td> "Adrift and at Peace" </Td> <Td> Allison Liddi - Brown </Td> <Td> Tony Phelan & Joan Rater </Td> <Td> December 2, 2010 (2010 - 12 - 02) </Td> <Td> 11.02 </Td> </Tr> <Tr> <Td_colspan="7"> Derek takes Cristina out on a fishing trip to help her with her problem . Teddy finds herself attracted to a patient who no longer has insurance, and ends up making a shocking suggestion . Lexie deals with a nurse who refuses to take orders from her and realizes she has to ask Mark for help . Arizona comes back, but Callie shuts the door in her face . </Td> </Tr> <Tr> <Th> 137 </Th> <Td> 11 </Td> <Td> "Disarm" </Td> <Td> Debbie Allen </Td> <Td> Krista Vernoff </Td> <Td> January 6, 2011 (2011 - 01 - 06) </Td> <Td> 11.64 </Td> </Tr> <Tr> <Td_colspan="7"> The doctors of Seattle Grace - Mercy West have to treat victims of a mass student shooting at a nearby college, and are confronted with their own trauma memories . As most of the doctors work to save the shooting victims, Teddy learns she is operating on the shooter . Some staff leave the OR, but Christina stays and settles in . </Td> </Tr> <Tr> <Th> 138 </Th> <Td> 12 </Td> <Td> "Start Me Up" </Td> <Td> Mark Jackson </Td> <Td> Natalie Krinsky </Td> <Td> January 13, 2011 (2011 - 01 - 13) </Td> <Td> 12.15 </Td> </Tr> <Tr> <Td_colspan="7"> All the residents are appointed a med student for the day, whom they are supposed to teach . As the med students evaluate their teachers, they all receive negative evaluations, except for Alex . He has a fling with the young woman who had been assigned to him . Teddy faces difficulties as she has to make life - changing decisions for her patient, of whom she is the legal spouse . Arizona attempts to reconcile with Callie, but she refuses, finally revealing that she is pregnant with Mark's child . </Td> </Tr> <Tr> <Th> 139 </Th> <Td> 13 </Td> <Td> "Don't Deceive Me (Please Don't Go)" </Td> <Td> Kevin McKidd </Td> <Td> Mark Wilding </Td> <Td> February 3, 2011 (2011 - 02 - 03) </Td> <Td> 11.18 </Td> </Tr> <Tr> <Td_colspan="7"> Derek starts his Alzheimers clinical trial and reluctantly includes Meredith as an assistant . Bailey starts tweeting during her surgeries, a concept that Webber opposes . He approves it after seeing what a valuable teaching tool it can be, and accepts suggestions from surgeons outside Seattle who are monitoring the surgery . Mark tells Lexie about Callie's pregnancy, resulting in her refusal to continue their relationship . Callie is overanxious about the health of the fetus, and struggles with the roles to be played by the three adults . </Td> </Tr> <Tr> <Th> 140 </Th> <Td> 14 </Td> <Td> "P.Y.T. (Pretty Young Thing)" </Td> <Td> Steve Robin </Td> <Td> Austin Guzman </Td> <Td> February 10, 2011 (2011 - 02 - 10) </Td> <Td> 10.47 </Td> </Tr> <Tr> <Td_colspan="7"> Meredith and Lexie's father, Thatcher, is admitted to the hospital with kidney stones . Much to Lexie's shock, he is accompanied by a 20 - year - old girlfriend, Danni . Alex conflicts with the hospital's newest OB / GYN, but unintentionally wins her respect by remaining concerned over a case from which she dismissed him . Mark tasks Avery to find out what is upsetting Lexie, causing Avery to find Lexie frustrated about people around her making major life changes, such as her father and Mark . Webber offers Meredith the chance to lead a clinical trial to test cultivated cells for diabetes treatment, which her mother had developed, but she chooses to remain on her Alzheimer trial with Derek . </Td> </Tr> <Tr> <Th> 141 </Th> <Td> 15 </Td> <Td> "Golden Hour" </Td> <Td> Rob Corn </Td> <Td> Stacy McKee </Td> <Td> February 17, 2011 (2011 - 02 - 17) </Td> <Td> 10.24 </Td> </Tr> <Tr> <Td_colspan="7"> Meredith runs the ER for a night, and time is shown to be critical . Meanwhile, Bailey sneaks off with Eli and gets into a little mischief . Everyone is surprised when the Chief's wife, Adele, shows up as one of the ER patients . </Td> </Tr> <Tr> <Th> 142 </Th> <Td> 16 </Td> <Td> "Not Responsible" </Td> <Td> Debbie Allen </Td> <Td> Debora Cahn </Td> <Td> February 24, 2011 (2011 - 02 - 24) </Td> <Td> 9.13 </Td> </Tr> <Tr> <Td_colspan="7"> Meredith must choose between her fertility treatments and her eyesight when she begins having trouble seeing, and stops the medication . Mark is emphatic about being consulted on decisions about the baby . April discovers there's more to Dr. Stark than first appears . </Td> </Tr> <Tr> <Th> 143 </Th> <Td> 17 </Td> <Td> "This Is How We Do It" </Td> <Td> Edward Ornelas </Td> <Td> Peter Nowalk </Td> <Td> March 24, 2011 (2011 - 03 - 24) </Td> <Td> 10.28 </Td> </Tr> <Tr> <Td_colspan="7"> Richard is desperate for Derek and Meredith to accept Adele into their Alzheimer's trial, and she is accepted . Meanwhile Mark and Arizona have conflicting ideas of the kind of baby shower Callie wants, Teddy is freaked out when Henry has another health complication--leaving them both a little exposed . The--competitiveness among the residents for the Chief Resident position is amplified when Richard receives the green light for his diabetes clinical trial . </Td> </Tr> <Tr> <Th> 144 </Th> <Td> 18 </Td> <Td> "Song Beneath the Song" </Td> <Td> Tony Phelan </Td> <Td> Shonda Rhimes </Td> <Td> March 31, 2011 (2011 - 03 - 31) </Td> <Td> 13.09 </Td> </Tr> <Tr> <Td_colspan="7"> In a series first, the music that has been at the heart of the show and been beloved by fans is used extensively in Episode 17, Grey's Anatomy: "The Music Event". While driving to a weekend B&B, Arizona proposes to Callie . The two are hit by a truck, and Callie suffers injuries that threaten both her life and that of the fetus . As the hospital staff work together to try and save them both, different individuals take the lead in singing such songs as "Chasing Cars" (Snow Patrol), "How to Save a Life" (The Fray) and "The Story" (Brandi Carlile), heightening the emotionality of events . Kate Walsh makes a guest appearance as Addison Montgomery . </Td> </Tr> <Tr> <Th> 145 </Th> <Td> 19 </Td> <Td> "It's a Long Way Back" </Td> <Td> Steve Robin </Td> <Td> William Harper </Td> <Td> April 28, 2011 (2011 - 04 - 28) </Td> <Td> 10.67 </Td> </Tr> <Tr> <Td_colspan="7"> Everyone pulls together to help Callie and baby Sofía on their painstaking journeys to recovery in hopes of allowing mother and baby to finally meet . The sudden death of a clinical trial patient has Derek proceeding with more caution, while Meredith makes a calculated and risky move; Alex treats a cranky old rich woman dying of cancer and gets an idea for a grandiose endeavor that is sure to get him the Chief Resident spot; and Teddy is pleasantly surprised by the return of a familiar face . </Td> </Tr> <Tr> <Th> 146 </Th> <Td> 20 </Td> <Td> "White Wedding" </Td> <Td> Chandra Wilson </Td> <Td> Stacy McKee </Td> <Td> May 5, 2011 (2011 - 05 - 05) </Td> <Td> 10.11 </Td> </Tr> <Tr> <Td_colspan="7"> As Callie and Arizona's wedding approaches, the couple quickly realize that the day they've been looking forward to is not turning out the way they'd envisioned . Meanwhile Alex continues to make the other residents jealous as he appears to be the top contender for Chief Resident . While Dr. Andrew Perkins presents Teddy with a very tempting proposition, Meredith and Derek make a life - changing decision . </Td> </Tr> <Tr> <Th> 147 </Th> <Td> 21 </Td> <Td> "I Will Survive" </Td> <Td> Tom Verica </Td> <Td> Zoanne Clack </Td> <Td> May 12, 2011 (2011 - 05 - 12) </Td> <Td> 9.63 </Td> </Tr> <Tr> <Td_colspan="7"> Personal and work pressures are adding up and have Meredith visibly on edge, Owen conducts formal interviews for the Chief Resident position, Cristina grows increasingly defiant, Alex and Lucy's undefined relationship gets tested, and Jackson suddenly backs out of the Webber's diabetes trial . </Td> </Tr> <Tr> <Th> 148 </Th> <Td> 22 </Td> <Td> "Unaccompanied Minor" </Td> <Td> Rob Corn </Td> <Td> Debora Cahn </Td> <Td> May 19, 2011 (2011 - 05 - 19) </Td> <Td> 9.89 </Td> </Tr> <Tr> <Td_colspan="7"> News of Meredith's dishonesty in the clinical trial comes to light, leading to unanticipated consequences for both her and others . Cristina finds herself in a compromising situation, which forces her to decide between her career and her relationship . Meanwhile, Owen posts his decision for chief resident and Teddy makes a surprising choice regarding her love life--and her future . </Td> </Tr> </Table> <Tr> <Th> No . overall </Th> <Th> No. in season </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original air date </Th> <Th> U.S. viewers (millions) </Th> </Tr>

When does christina yang come back in season 7