Critical Incident - Season 4

A Surrey police officer receives life-changing injuries when his patrol car is involved in a terrifying high-speed crash. Two officers in Cheshunt risk their lives and run into a burning building.

In London, a Met officer is attacked by a man wielding a four-foot-long broadsword. An officer in York must use all her strength and courage to rescue a colleague who has fallen into an icy river.

Two officers in south Wales are confronted by a man with a kitchen knife. In Leeds, a traffic cop puts his life at risk to save a driver trapped in his van. Surrey Fire and Rescue service are faced with a huge wildfire.

A Birmingham police officer is stabbed in the neck by someone he is arresting. In Hull, an officer and his faithful police dog come under a violent attack. After a life threatening injury, a West Midlands paramedic has found a new lease of life thanks to an unusual hobby.

Two paramedics talk of their experience on the scene of the 2017 London Bridge attacks. In Manchester, the police launch a new initiative to crack down on knife crime. After losing his eye, a former police officer has returned to the force in a new role.

Two RAF aircraft are dispatched to save the life of a sailor in heavy seas 800 miles out in the Atlantic. Essex police film dangerous drivers from an HGV, with life-changing results for some of them. A paramedic in Barry in Wales finds herself the victim of a terrifying assault.

999ers on the scene look back at the 7/7 attacks in London. Police are called as a volatile patient assaults two paramedics on the Isle of Wight. In Manchester, a young police dog and his handler face a man armed with a crowbar.

A Merseyside police officer is run over as he searches a van thought to be connected to drug runners. A call handler in Hampshire saves the life of a baby who isn't breathing. After a life-changing injury, a former PC is finding his feet again.

In London, emergency responders remember the nightmare they faced during the Westminster Bridge terror attack. In Staffordshire, a newly taser-trained PC must decide whether to fire her weapon for the first time, at a machete-wielding woman.

In Staffordshire, two officers save the life of a man in a burning building. In Avon and Somerset, police tackle county lines drug dealing, and in Norfolk, two firearms officers come face to face with a gunman in a car park.

In Wakefield, a police officer is the victim of a violent attack. Greater Manchester Police are tackling the issue of knife crime in the city. The RAF are called in to help transatlantic rowers in distress.

Two paramedics talk of their experience on the scene of the 2017 London Bridge attacks. In Manchester, the police launch a new initiative to crack down on knife crime. After losing his eye, a former police officer has returned to the force in a new role.

A Fire crew in Burnley comes under attack on their busiest night of the year. In Swindon, two paramedics are violently assaulted by a patient, and police in Derbyshire tackle the problem of county lines drug gangs.

In London, a paramedic is sexually assaulted on a call. Firefighters in Nottinghamshire tackle one of the biggest blazes they've ever seen, and the Police Federation recognise the actions of officers across England and Wales.

It's a busy night in Newcastle for Northumbria Police as they work the night-time economy shift. We take a look at one of the most dangerous specialties in the police – firearms. The National Police Air Service face danger in the air.