Meredith Grey starts her first day as a surgical intern at Seattle Grace Hospital, unaware that she just had a one night stand with one of the doctors. Meredith struggles with the rigors of her first days at work while she cares for her ailing mother.
Meredith puts her career in danger when she tries to save a newborn in the hospital nursery. The surgical team works to save young woman who was brutally attacked.
The annual bike messenger race fills the emergency room with cyclists, prompting the interns to compete to treat the most severe injuries first.
Christina takes an assignment with a woman who happened to have been the scrub nurse of Meredith's mother. George begins to feel like Izze and Meredith are immasculating him, while Alex decides to splash pictures of Izze's sexy magazine shoot across his locker area. Meanwhile, Meredith continues to struggle with her mother's illness.
Meredith believes she may have made a grave error during surgery, and her subsequent admission of that belief may cost her her medical career. Meanwhile, Izzie tries to prove that not all doctors are obssessed workaholics by throwing a party for her new boyfriend at Meredith's house, but her plans are thrown off course as the big night approaches.
Alex makes an idiot of himself in front of Annie, a shy patient who has an enormous tumor, after working hard to befriend her.
Meredith has Derek spend the night at her house and tries to keep everyone from finding out. George thinks an anesthesiologist might be drinking while at work, but is afraid to say so.
Meredith grows annoyed with Derek for being so secretive about his life. An Orthodox Jewish girl's religious beliefs makes it difficult for Alex to treat her illness. Cristina argues with a 40-year-old pregnant cancer patient about her treatment.
Many staff members at the hospital are affected by the outbreak of a sexually transmited disease. Cristina and Izzie must deal with a patient whose wife and daughter are fighting over his care.