The BBC has revealed a first look at Charlie Fairhead (Derek Thompson) and Ethan Hardy's (George Rainsford) return to Casualty as the medical drama marks 40 years.
The soap is celebrating its big anniversary on Saturday (5 September) with a special double bill, which will centre on a major incident that throws Holby into chaos.
“Lives hang in the balance and the ED team are pushed to their limits in a tense and emotionally charged story that brings together some of the show's most beloved characters," the official synopsis teases.
"As the fallout continues, a major rescue operation unfolds, forcing impossible life-or-death decisions and testing the courage, resilience and leadership of those at the heart of the hospital.”
Thompson first appeared on the soap as senior charge nurse Charlie in the show's very first episode in 1986, and was the longest-serving cast member when he departed from the BBC series in 2024.

The character left Holby City ED after deciding to retire when a patient endangered his life and stabbed him while trying to steal medical supplies from the hospital.
Rainsford, meanwhile, played doctor Ethan Hardy between 2014 and 2023. Ethan departed from the ED after deciding he wanted a stronger relationship with his baby son Bodhi.
Alongside Thompson and Rainsford, other cast members set to star in the upcoming anniversary episodes include Olly Rix, Elinor Lawless, William Beck, Melanie Hill, Barney Walsh, Neet Mohan and Charles Venn.
Also appearing are Sammy Dobson, Kirsty Mitchell, Di Botcher, Anna Chell, Sarah Seggari, Michael Stevenson, Milo Clarke, Naomi Wakszlak and Aron Julus.
Casualty's 40th anniversary specials air at 8pm on Saturday 5 September on BBC One and iPlayer.
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