As Waterloo Road returns to BBC1 (Thursday, May 2), Philip Martin Brown reveals his character, teacher Grantly, is deathly ill…

At the end of last term Grantly was given shocking news about his health. How is he coping?

“His struggle continues. He’s put on dialysis, but it’s only a stop-gap until a kidney donor can be found. Although he’s grumpy he’s also got a dark sense of humour, rather like my own, so if he can make a joke out of a grim situation he will!”

How does his illness effect his wife, dinner lady Maggie?

It’s harder for Maggie than it is for Grantly, because she has to deal with the emotional roller-coaster of their situation.”

When Grantly returns to the school this week he keeps his illness a secret from colleagues and students. Why?

”Grantly’s a proud man. When his first wife Fleur was ill with Alzheimer’s he didn’t want people to know because he’s very private. He wants to keep work separate from his home life. Grantly’s also embarrassed about what he’s going through. He doesn’t think the process of home dialysis, and all the paraphernalia he needs to feel better, is very dignified.”

What does the future hold for him?

“This storyline is going to run for quite a while. Grantly gets progressively weaker while they’re looking and hoping for a donor. It gets bleak, without a shadow of a doubt, but there are definite glimmers of hope for him.”

How do you think fans of the show will react?

”We’ve touched on storylines like this before, with Fleur’s Alzheimer’s and Sambuca’s death, so it will be interesting to see. I think there will be a mixed reaction.”

What do you think about Grantly’s latest twist of fate?

“One of the reasons I’ve stayed in Waterloo Road for eight years is I never know what they’re going to throw at me next. This is a very meaty storyline. Grantly knows his wayward lifestyle, and letting his blood pressure go unchecked for so long, has left him in this situation. The variety of humour and pathos makes this job a joy!”