This September will mark 40 years since we first stepped foot into Holby City Hospital.

A new trailer released tonight (25 July), which can be viewed below, has shown how Casualty – the longest-running primetime medical drama in the world – plans to mark the milestone anniversary.

Set to the tune of “Happy Birthday”, we see a fireball engulf the skies of Wyvern, from the view of Bristol’s Clifton Suspension Bridge. Clinical lead Flynn Byron (Olly Rix) is walking along the bridge as the explosion erupts.

Outside of the ED, consultant Dylan Keogh (William Beck), clinical fellow Rash Masum (Neet Moham), senior staff nurse Rida Amaan (Sarah Seggari) and her junior Cam Mickelthwaite (Barney Walsh) stand in shock, and there’s a brief glimpse of an unnerved Dr Stevie Nash (Elinor Lawless).

Suddenly, a cluster of incoming calls flood across a computer screen in the ambulance station, and managing paramedic Jan Jenning (Di Botcher) watches on nervously.

Stevie and Flynn face a race against time and fight for survival in the back of an ambulance, Rida tackles an unruly patient, and Dylan sobs after receiving news of a horrific personal tragedy.

Armed police then approach the hospital, and a final shot shows glowing ambulance lights from beneath the surface of some murky water.

Radio Times was on set with the Casualty team during the making of these episodes, and will have an exclusive look behind-the-scenes with interviews from cast and crew this autumn.

Stevie crouching in the back of an ambulance in a scene from Casualty

Elinor Lawless plays Stevie Nash. BBC Studios

Airing on BBC One and iPlayer on Saturday 5 September, the special double-bill will see the show’s beloved characters placed in a “major high-stakes incident” that is set to throw the emergency department into chaos.

Lives will hang in the balance as the staff are stretched to their limits, and in the midst of the fallout, a major rescue operation unfolds.

We’ll see an “impossible” life-or-death decision, while the “courage, resilience and leadership” of those at the hospital will be tested.

Rash Masum in a scene from Casualty

Neet Mohan plays Rash Masum. BBC Studios

Completing the cast for the episodes are Melanie Hill, Charles Venn, Sammy Dobson, Kirsty Mitchell, Anna Chell, Michael Stevenson, Milo Clarke, Naomi Wakszlak and Aron Julus.

The BBC soap has also teased that these episodes will signal an “exciting new chapter”, as it prepares for major changes next year. After being put out to tender – which means to find another production company – a new contract was signed with BBC Studios to make the next three series.

This is also reflected in the name of the trailer: “Life Begins at 40”.

Part of the new deal was to move the story away from Holby City after four decades, and focus on a new Welsh hospital. Casualty has already been produced from studios in Roath Lock, Cardiff, since 2011.

Previous episodes of Casualty are available to stream on BBC iPlayer now.

Casualty returns on Saturday 5 September on BBC One and 6am on iPlayer.

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