In the latest chapter of Casualty’s Learning Curve boxset, the gap between what Stevie Nash sees and what Kim Chang is actually living with grows wider — and more worrying. While Stevie continues her trademark tough-love approach to mentoring, she remains completely unaware that the junior doctor she’s pushing so hard is quietly battling an eating disorder.

From Stevie’s perspective, Kim is a capable but fragile trainee who needs structure, pressure, and high standards to survive in the ED. She believes in pushing her residents to prove themselves, convinced that resilience is built through challenge rather than comfort. It’s an approach that has worked for her before — and in some ways, it’s already working with Kim, who has shown flashes of real clinical confidence and strong instincts under pressure.

But what Stevie can’t see is the cost.

Behind the scenes, Kim’s need for control is tightening its grip. The long shifts, the constant scrutiny, and the fear of making mistakes all feed into a mindset that tells her she has to be perfect — not just at work, but with her own body. When she grabs food with Matty Linklater after a draining shift, it looks like a small, healthy step toward normality. In reality, it becomes another trigger.

Later, Kim pushes herself into overexercising, trying to “undo” the meal in a way that feels both urgent and compulsive. It’s not about fitness. It’s about fear, guilt, and a desperate need to stay in control of something when everything else feels uncertain. The contrast is striking: in the ED, she’s learning to trust her hands and her training; outside of it, she’s locked in a private battle that no one else seems to notice.

Stevie, meanwhile, continues to mentor Kim with the same uncompromising standards. When Kim struggles, Stevie assumes it’s nerves or inexperience. When Kim succeeds, she sees proof that the pressure is working. What she doesn’t see are the warning signs: the anxiety around food, the rigid routines, the way Kim’s confidence collapses the moment the shift ends.

That blind spot makes this storyline particularly tense.

Stevie isn’t being careless or cruel — she’s being exactly who she’s always been. The problem is that Kim’s struggle doesn’t look like the kind of weakness Stevie knows how to spot. There are no obvious mistakes, no dramatic breakdowns in the resus room. Instead, there’s quiet overexertion, hidden panic, and a growing imbalance between what Kim shows the world and what she’s actually coping with.

For Kim, the danger lies in how long she can keep this up.

She’s already proven she has the skill to work in Holby. She’s impressed Stevie with procedures and judgement. But the more she relies on control to get through each day, the more fragile that success becomes. Overexercising isn’t a solution — it’s a warning sign, one that suggests the pressure is starting to spill over into something far more serious.

As Casualty continues this storyline, the question isn’t whether Stevie’s approach will toughen Kim up. It’s whether someone will notice what’s really going on before Kim’s hidden struggle starts to affect her health, her work, or both.

For now, Stevie remains in the dark. And Kim keeps running — both literally and emotionally — hoping no one sees just how close she is to falling.