Casualty is back for a thrilling new box set this weekend, with the BBC offering a first look at what’s to come for the staff at Holby City ED.

The trailer for Internal Affairs sees Call the Midwife star Olly Rix making his Casualty debut as new clinical lead Flynn Byron, and he certainly has his work cut out for him.

In the trailer, Flynn can be seen introducing himself as he certainly ruffles some feathers among the Holby City doctors and nurses.” />

But Flynn isn’t the only person with their work cut out for them this season, with tensions brewing between Rida Amaan (Sarah Seggari) and Nicole Piper (Sammy T Dobson).

The trailer also shows Flynn involved in a devastating crash, an ambulance drive into the ED and a wedding!

But will wedding bells last for long, as the events at Holby City threaten to take precedence?

You can watch the trailer now.

The new 12-part box set begins on Saturday 15th March and also features Robert Bathurst (Downton Abbey) in the guest role of Russell Whitelaw, a top-tier surgeon who has commanded the operating room for years with his unmatched skill and domineering personality.

The synopsis for Internal Affairs adds: “As the new clinical lead consultant at Holby City ED, Flynn joins the NHS fresh from a tour of duty.

“He’s a man with a purpose, and with a fierce resolve to make a difference. He faces the challenge of instilling change in a system weighed down by bureaucracy, all the while grappling with the trauma he has experienced and a deception that threatens to be his undoing.”