Paediatric nurse Mahbuba deals with a baby who can't breathe, while Rebecca treats a deaf cardiac patient and military nurse Scott cares for a struggling asthmatic.

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.