Zoe burns her bridges in Saturday’s Casualty when she shows up late, defies clinical lead Connie, and ruins her own 40th birthday surprise by badmouthing her friends and colleagues!

Sunetra Sarker told What’s on TV why the stressed-out consultant decides to hang up her stethoscope and walk away from the job she loves – and the man who loves her…

Where is Zoe’s head when we catch up with her this week?
“To Zoe it’s a normal day where she happens to turn 40… until a series of incidences show her she needs to take stock of her life.”

How does it play out?
“It’s done really cleverly. Tracie Bennett returns as Molly, the resident tramp, in her recurring guest role. Because Molly isn’t actually Zoe’s friend or family she can say things to her that are on the nose. Molly makes Zoe look at her own life in more depth. Molly has a great story to tell and it combines with the crossroads Zoe finds herself at.”

How is her relationship with clinical lead Connie at this stage?
“Connie is always in the background – she’s an itch that Zoe can’t scratch away. Because Connie recommends she take a holiday, it becomes the last thing Zoe wants to hear, even though everyone else thinks she should take a break too!”

Meanwhile, Zoe’s having a secret affair with hospital porter Max. Is this part of her crisis?
“Earlier this year Zoe demoted herself as clinical lead because she’d rather deal with patients than the management. Then she did the last thing you’d expect a top consultant to do – get involved in a love tryst with Max the 30-year-old porter!”

What is it about Max that entices Zoe?
“As a consultant and a porter they have nothing in common. She saves lives and he delivers beds to a ward. But Max, bizarrely, relaxes her! His laidback attitude lets her be herself in a way she can’t be with patients, consultants or management. At work she keeps up a front, but drops her guard around Max.”

Max is smitten. How does he react when Zoe reveals she’s quit Holby ED and is dumping him too?
“Max is attracted to this woman, who really makes him laugh, but Zoe doesn’t believe he can be smitten with her. He’s a young indie-band guy and she thinks he can’t possibly be serious about her. Audiences will see Zoe try to end the relationship with him, but Max isn’t having it! Max keeps surprising her with his interest.”

But it’s not enough to make her stay?
“I’ve really enjoyed playing Zoe, but it’s time for her to leave. She’s exhausted and needs a break. And in this episode everything comes to a head and she needs to reassess her life.”