Casualty has cast former EastEnders star Annette Badland to play an important role in Charlie Fairhead’s final episode.

Actor Derek Thompson is leaving the medical drama after 38 years in the role, and this Saturday (March 16) marks his final episode.

It remains to be seen whether or not Charlie will survive, as at the end of the previous episode (March 9), the nurse was stabbed by troubled patient Kyle.

This week the team, including fan favourite returning character Zoe Hanna, rush Charlie to resus to try and save his life.

As he drifts in and out of consciousness, he flashes back to an important day early in his career before his long stint at Holby.

The flashback to the 1980s will begin with the surprise retirement party for Charge Nurse Shirley (played by Badland), which a young Charlie shows up to hungover.

Related: BBC denies reports Casualty is ending

Shirley gives Charlie some much needed advice, telling him he needs to pull his socks up if he wants to get the job he wants at Holby.

The nurse’s advice seems to come at just the right time, as soon after there is a nail bomb explosion that fills the hospital with casualties.

While Charlie’s life hangs in the balance in the present day, the flashbacks will show him responding to a difficult day at work, and will also uncover a hidden connection between him and doctor Stevie.

Badland is known for playing Aunt Babe in EastEnders, as well as a range of roles including landlady Mae in Apple TV’s Ted Lasso.

In an interview, Thompson has praised the writing in his final episode, which will see his iconic character exit the ED for good.

He said: “When I first read the script, I didn’t have to think about it at all, because it’s just great storytelling. The way Michelle Lipton wrote these episodes comes across like she’s written eight plays, taken from so many points of view.

“I don’t think there’s another writer who could have done it. I think my final two episodes are some of the best episodes of my career.”