As the action begins, a seriously ill man has been choppered in from a road accident. Vascular surgery specialist Lorraine Rappaport sets to work on the patient - but when office politics come into play, she is asked to step down, forcing hospital fellow Fiona Lomas to take over. But it soon becomes clear that she doesn't have the theatre experience of her colleague.
Consultant Glen Boyle takes control when a woman is brought in with a fence post impaled through her face - and insists on opening up the patient when she starts haemorrhaging, uncovering a heart-wrenching explanation for the injuries. Amid all the action, Fiona struggles to deal with the fact that she's working with her ex once again.
Tensions run high as the team works to save a cyclist who was involved in a serious collision with a HGV, and with the patient flatlining, Glen makes a bold move to try to turn things around. Meanwhile, the surgeon comes to a decision about the status of his relationship with Fiona.
The team sets to work on a badly beaten man covered from head to toe in lesions and lacerations - and interests are piqued by the discovery of a serial number branded on the patient's arm, suggesting he may be a slave labourer or a victim of trafficking. However, as the man's temperature soars, the doctors realise they may be dealing with a dangerous, and highly infectious, disease - and the trauma centre is forced into lockdown.
There is confusion in the the operating theatre after Lorraine returns to work, taking control from Glen as trauma team leader to treat a woman who has aballoonshot wound.
The tension between Glen and Lorraine continues to increase they go to the aid of a troubled patient who has jumped off the hospital's atrium walkway.
A shock is in store for the team when they treat an agitated patient who has been involved in a car crash. Glen delivers an overdue apology to Fiona, too.
The team feel the pressure more than ever when they treat a horrifically burned patient. Glen grows closer to Fiona, too, shedding light on his army days.
The prognosis does not look good as the team attempt to save a teenage drowning victim. It results in a standoff between Glen and Clive. A bold move is made by Fiona.
The victim of a dog attack is brought in with the dog still attached to him.
There are some obstacles to deal with as the team tackle one of their trickiest cases yet.
Stretched to the limit, the team hit the road to treat multiple victims involved in a traffic accident. Fiona, meanwhile, tries to keep her engagement a secret.
Devastated by news of Fiona's engagement, Glen races off, only to be involved in a life-or-passing emergency.