While enrolled in a demanding residency program, Meredith Grey and four other first-year surgical interns try to balance life and work at Seattle Grace Hospital.

The surgical staff tries to be optimistic as a young woman clings to life after a brutal attack; Meredith puts her career on the line to save a newborn in the hospital nursery; the other interns learn that it takes more than just medical knowledge to be good at their jobs.

When the annual bicycle messenger race takes place in Seattle, the hospital emergency room fills with an assortment of injuries, causing the interns to compete for the most severe cases; Derek and Burke vie for the Chief Resident's position; while Derek continues to pursue Meredith romantically, a patient flirts with George.

Cristina's encounter with a former nurse, now a patient at Seattle Grace, changes her forever.

Meredith believes she may have erred during surgery and endangered her career; nothing goes as planned for Izzie, who tries to throw a party for her new boyfriend.

Alex works hard to gain the trust of Annie, a shy patient with a gargantuan tumor, only to make a fool of himself in front of her later.

Derek and Meredith try to be discreet after spending the night together at her house; George is reluctant to voice his suspicions that an anesthesiologist is drinking on the job.

Meredith becomes disenchanted with her ignorance of parts of Derek's life; Alex treats a patient whose religious beliefs jeopardize her chances for recovery; a 40-year-old pregnant woman diagnosed with cancer disagrees with Cristina's advice.

The outbreak of a sexually transmitted disease affects several members of the hospital staff; Izzie and Cristina worry about a patient whose wife and daughter are at odds over his care.