I arrived at the Sunrise ten minutes before rehearsals were due to start, yet somehow still felt late. Finding the communal green room empty, I dropped my bag and coat on a free table and hurried through corridors towards the stage. Voices sounded from out front. Had I got the time wrong? Being late to first rehearsal wouldn’t make a good impression.

I weaved past stagehands in the wings and emerged to find the principal cast huddled with the director, Simon. He had his arm around the shoulder of a young woman, and everyone smiled while she took a group selfie on her phone. I was still very much on the outside of acting scene gossip, having ignored it altogether for the past ten years, so I had no idea if this was Simon’s daughter, his latest wife, a PA, or whatever. But they were clearly on good terms, so I decided I should make an effort.

Ted, the actor playing the eternally patient husband Martin to my harrassed mother Melanie, noticed me step on stage and discreetly cleared his throat. The others turned like a pack of startled meerkats then parted so I could approach Simon and his blonde companion.

I took the initiative and walked forward confidently. ‘By my watch I’m early, but seeing you all here makes me wonder,’ I laughed, and before anyone could contradict me, I put out a hand to greet the young woman. ‘Good morning. You’ve met everyone else, so you might have already guessed I’m Gwinny.’

‘Oh yeah, of course,’ she smiled, handing her phone to Simon. ‘This is so good of you, thank you. I’m Violet, obviously.’

‘… Obviously,’ I agreed, envying the confidence of youth. She probably had a million followers on social media, so why wouldn’t it be obvious?

(I know what social media is, I’m not a Luddite. My new agent had suggested I create a profile and get involved, to let people see ‘the real Gwinny’. But when I spent an hour looking around, it seemed what people really wanted to see was either beautiful young people posting pictures of themselves in sunny locations, or angry old people arguing with each other about today’s tabloid frenzy. I doubted there was an audience for back pain, varicose veins and house renovations.)

‘Let’s begin,’ said Simon, clapping for attention. ‘Places, please.’

I reached for my lines then remembered I’d left my bag backstage. Ted and I weren’t on until scene three, though, so I’d have time. As everyone scurried to position, I passed him in the wings and whispered, ‘I need to get my lines from the green room. Cover for me, I’ll be back in a minute.’

Before he could reply, a stagehand handed me a stack of pages. I thanked her and flipped through to scene three, only to find it wasn’t there. ‘Darling, I think you’ve got these mixed up,’ I called after her. ‘These are for—’

‘Places, Gwinny, places!’ Simon bellowed from his seat facing centre stage. ‘Get with it, you’re in scene one now.’

Confused, I turned back to the opening pages and scanned in vain for my character. Had there been rewrites already?

‘Sorry, Simon, I don’t see Melanie in the opener. Are these definitely the latest sides?’

‘What? No, you’re Margory. Violet is playing Melanie.’

I was so still I could have won a prize. Vaguely aware that everyone else had frozen too, I glanced over at Violet. She stood in the wings, suddenly fascinated by her own script.

‘Say that again?’

The director sighed theatrically. ‘You’re playing Margory now. The grandmother. Violet is playing Melanie, the mother. For heaven’s sake, didn’t anyone tell you?’

Blood rushed to my cheeks. I fought to keep my voice steady as I walked downstage to the footlights and said, ‘Who, Simon? Who exactly would have told me? You’re the director.’

‘Yes I am, and that’s why I’ve made the decision to recast with someone closer to the character’s age. Now don’t fuss, Gwinny. Find your mark and let’s go.’

I did, and proceeded to stumble my way through unfamiliar lines and an unfamiliar headspace for the first run-through. I kept reminding myself that I was no longer a star, or even much of a recognisable character actor. I should have known that landing a central role so soon was too good to be true. This was what I’d dreaded most about resuming my career: having to start back at the bottom of the ladder, like a struggling young actress all over again but with several decades of accumulated aches, pains and wrinkles to contend with.

I didn’t blame Violet. Assuming she wasn’t sleeping with Simon, she’d done nothing more than be a pretty ingénue. Yes, she was twenty years too young for the part, but make-up could take care of that. In her position I would have done the same.

At lunch break I found a private area and called my agent, ‘Bostin’ Jim Austin.

‘Bostin Agency,’ he answered in his thick Brummie accent. Bostin was a nickname he’d acquired at school in Birmingham, apparently local slang for brilliant. It takes all sorts.

‘It’s Gwinny. What the hell’s going on with Mixed Mothers? They want to recast me!’ Furious, I related what had happened while Jim patiently tutted in all the right places.

‘Believe me, I would have told you if I’d known about it,’ he said when I finally paused to breathe. ‘But I don’t think there’s much I can do.’

‘Surely it’s a breach of contract,’ I sputtered. ‘Margory has a quarter of the lines Melanie does. Are they at least going to pay me the same?’

He hesitated. ‘Now there’s an idea. Leave that with me. The thing is, do you really want to cause a fuss?’

There was that word again. ‘I’m hardly being an unreasonable diva. I was cast in a role, and I expect to play it.’

‘I get that. But now you’ve been re-cast, and a woman of your experience knows that sometimes happens on small productions. Especially when they can suddenly get a big name from TV.’

‘She’s practically a teenager. How has she been around long enough to be any kind of name?’

‘Are you serious? Didn’t you watch Eastenders last year?’

‘Last year I was somewhat busy caring for my dying father.’

After a pause he said, ‘OK, I apologise for that. But if we’re going to work together, I need two things. First, you have to take more of an interest in the business. Second, if I can be frank, remember that you’re basically starting over from scratch, and with a handicap. You don’t want a reputation for making trouble.’

I seethed quietly at being called a troublemaker when none of this was my doing. But I knew exactly what ‘handicap’ he meant. There was no shortage of older women vying for stage parts, thanks to the lack of decent roles on TV. If word got around that I was difficult to work with, or even (gasp!) ungrateful, I’d be consigned to the do-not-hire pile.

‘Five minutes,’ came a shout from the corridor.

I pushed my anger deep down inside, took a long, slow breath, and said, ‘All right, deal.’ Struck by sudden inspiration, I added, ‘By the way, I don’t suppose you happen to know any good builders? My house needs a bit of work.’

‘I do, actually. Just had our loft done, and quite reasonable too. I’ll text you his number.’

Before I could ask whether Bostin Jim and I shared a definition of ‘quite reasonable’, he ended the call. I threw down my phone and reread grandmother Margory’s lines.

At ten past four I stepped out of the stage door and was assaulted by a black Labrador. Thankfully it was a loveable attack, all wagging tail and lapping tongue, so I crouched to greet him and fuss his ears. ‘Hello, Ronnie,’ I said between licks.

Ronnie belonged to my friend DCI Alan Birch, retired, formerly a senior detective in the Met and presently standing behind his dog as it tried to drown me. Seeing Birch there, stoic and grounded, it struck me how like a faithful Lab he was himself. We’d become friends by tripping over a murder case, when Tina had been accused of killing her husband-to-be. With Birch’s help I uncovered what the police had failed to, unmasking the real murderer, and through it all his loyalty had never wavered. Tall and wide-shouldered, with grey cropped hair and a full moustache, he couldn’t look more like an ex-policeman if he tried. But beneath a firm brow he had the most delightful bright blue eyes, and wasn’t to be underestimated.

Nevertheless, glad as I was to see a friendly face, it was a surprise. ‘I don’t recall telling you when I’d finish today,’ I said. I wasn’t entirely sure I’d mentioned rehearsals at all.