Meredith breaks a hospital record; the doctors are sent scrambling in the wake of a massive overdose within the community; Jackson wants to take Maggie camping; Levi and Nico's relationship continues to develop.
A sea of patients flood Grey Sloan Memorial after gunfire goes off at a parade. A blast from the past throws Maggie off her game on the same day that Meredith tries to talk to her about dating Deluca. Meanwhile, Owen ...
Izzie and Cristina are assigned a close-to-brain-dead John Doe who may be a viable candidate for organ donation, and helpful to George's patient, who needs a new liver. Meanwhile, Meredith and Alex butt heads over a patient of their own.
Alex uses Izzie's modeling against her, and her last ad causes a patient to reject her care. Meredith finds parallels between a patient and her mother, and Christina must deal with a hospital-savvy patient.
Meredith worries she did something wrong during a heart bypass, an error in a past procedure is discovered, putting a staff member's conduct under scrutiny, while a party thrown by Izzie to introduce her boyfriend becomes a fiasco.
A woman with a massive tumor is admitted, with all the surgeons required to scrub in. In their absence, Meredith is assigned a patient with Parkinson's and, because Alex's pager is not working, Izzie is left in charge of the floor herself.
Izzie and George find out about Meredith and Derek, while Cristina makes a discovery of her own. George thinks an anesthesiologist is drinking on the job, and Meredith deals with a young girl who has had illegal surgery.
Meredith wants to learn more about Derek, but he remains cagey. Meanwhile, a supposedly psychic patient proves bothersome, Alex must convince a young girl to agree to a life saving operation, and Cristina is conflicted about her pregnancy.
George discovers he has syphilis, and it soon emerges that the disease is rampant among the hospital staff. Suspicious about a patient's death, Izzie and Cristina perform an unauthorized autopsy, and Richard requires an emergency operation.