In Queen Alexandra Hospital's Critical Care Unit, one of Advanced Nurse Practitioner Caroline's patients is deteriorating rapidly. George, who had a heart attack three days ago, has a dangerous build-up of fluid on his lungs. She decides the only way to save his life is to put him on a ventilator, but it's not without risks; this could also cause his heart to stop. Caroline must make a very difficult call to George's wife to explain the perilous situation.

In Paediatrics, Mahbuba investigates why a two-year-old has such a high temperature, Cardiac nurse Rebecca prepares for an emergency admission and Kat cares for a woman after breast cancer surgery.