Hathaway's obstetrics nurse, Abby Lockhart, shows up for work in the er--not as a nurse. Abby's a third-year medical student starting her er rotation. She learns working in the er differs greatly from working in the obstetrics department after a patient bites her arm, and Abby makes a misdiagnosis on a patient who eventually suffers a heart attack.

Cleo treats 13-year-old Marty Dorset (CHRISTOPHER MARQUETTE), a boy who is noticeably small for his age. An examination reveals bruises on his back, and Marty explains that the kids at school beat him up because of his size. Marty also suffers from infected needle marks on his thighs as a result of taking human growth hormones he obtains off the internet. But the needles he keeps re

using may be responsible for bacteria in his bloodstream causing a serious heart infection. Because Medicaid refuses to cover the treatment, Benton arranges free plastic surgery on a girl with a severe facial disfigurement from a dog-bite. But Romano refuses to allow free use of the hospital operating room. When Romano becomes too ill from kidney stones and can't finish a surgery, Benton completes it for him. Benton expects a favor in return--operating room time for the girl's surgery. Romano doesn't object.

Kovac and Hathaway administer to a chronically ill 3-year-old boy. Hathaway proves that his mother, Kathleen Brant (GIULIANA SANTINI) intentionally induces the boy's symptoms. Isabelle Corday (recurring guest star JUDY PARFITT) arrives in Chicago as a guest lecturer and meets with her daughter, Elizabeth. Cleo shows Greene that she can play basketball as well as a man.