Rhoda Bradley is a busy mum frustrated with her job as a supermarket check-out assistant. When she discovers the health service is recruiting new doctors, she decides to enrol in medical school - but the move doesn't go down too well with either her competitive sister Maddy, or her husband Tony, who fears the decision will turn their lives upside down.
Rhoda begins to settle into life at medical school, but the discovery that her resentful sibling Maddy is the nursing sister on her ward leads to a painful confrontation when a long-kept secret is uncovered. The apparently simple task of taking patient histories also leads to repercussions for the trainee doctor, while Tony struggles to organise the household and show up for work on time.
Rhoda mistakenly thinks her new-found medical knowledge can help her best friend Jules, but her actions cause a rift between them. The trainee doctor must then escape the attentions of smooth-talking Will when the students are let loose on a cadaver and have their emerging diagnostic skills tested in a role play class. Meanwhile, Tony is approached about a job that would get him out of the garage.