ELAINE C Smith has tears in her eyes as we chat.

Not, flowing-down-cheeks-like-little-streams tears or anything, but small pools are certainly filling up in the actress's baby blues.

Now, it has to be said I've said nothing to upset Scotland's biggest female star.

The emotional overflow stems from her work moments earlier in rehearsals for new play, This Wide Night.

Elaine stars alongside Field of Blood star Jayd Johnson in the new theatre play by Chloë Moss.

She plays Lorraine, released from jail after a 12-year sentence, who looks up her cellmate who she was so close to.

But why the waterworks?

"When I was younger I'd be forever hearing actors saying things like 'I was so immersed in my role I took my character home with me," says Elaine, forcing a smile through a gentle sob.

"And when I heard this at the time I was thinking 'Shut up!' But now I have to admit that at the age of 55, for some reason, I find myself caught up in the parts I play.

"I suppose it happened when I played Shirley Valentine, and certainly Susan Boyle in her life story.

"And more recently when I've been working on Rab C Nesbitt, I have been going home feeling a bit Mary'doll, a bit unattractive and disorientated.

"But I didn't expect to be greetin' the way I have been today."

Elaine reveals more of the plot and answers emerge.

"What we learn is her friend Marie, who she once had this incredible bond with, was released from prison sometime back, but she hasn't been back to visit Lorraine for six months.

"Lorraine can't believe this; the pair had made plans to get a flat together. Suddenly Lorraine is suddenly lost. And this woman has got to me."

Elaine adds: "I've been talking to director David Greig about her this morning, and I guess that's why I feel so emotional.

"I love the process of stripping away at the character, but in doing that I had to go into the darkness.

"I began to really wonder what it would really be like for a woman who gets out of prison after 12 years.

"Everything about her life is different. She gets on a bus to go see her pal, but buses are different. The money is different. And she's on her own, with no one to go back to.

"David asked me what I was feeling as we talked about Lorraine's back story and asked me what my overriding feeling was. I didn't have to think. I just said 'Terror'."

Elaine feels raw because she's been getting into the mind of the character to great effect.

But a smile envelops her face as she reveals the moment that really set her over the edge. It was a slip-of-the-tongue moment during tea-break.

The actress, casually, asked David Greig if he'd seen Glasgow Girls, the hit musical play being reprised at the Tron.

"I said 'I haven't seen it, but somebody told me it was terrible," she said.

David Greig offered a generous smile then revealed he was in fact the writer of the acclaimed piece of theatre.

Elaine wanted the ground to open up and swallow her.

"I said to him 'That just proves you should never quote what folk say in the bar at Oran Mor'. But I felt bad about what I'd said to him.

"Then when we went back into rehearsals I took the terror of this faux pas with me.

"And added to Lorraine's story, it's all been a bit too much."

However, after an hour's chat in the ­confessional, Elaine feels ready to re-embrace her character.

The comedy star appreciates theatre life is not all about making audiences cry with laughter.

And sometimes in playing drama, it's the actress who does the crying.

"I really want to make this part work," she says.

"It's so well written and David is a great director.

"You know, he gave me a great note on how to play Lorraine.

"He said 'When she goes to meet her one-time she's Columbo!' And he's right. Lorraine goes fishing, asking everything but the obvious question in order to get the truth."

Smith is now laughing. She's the old Elaine, soon raving about the referendum debate, pulling out her soap box to sing the praises of independence then leaping back down to talk of the excitement of becoming a grandmother in May.

At the end of the year, she will be starring in panto again in Aberdeen.

"When you think about it, I've nothing to greet about." She adds, grinning.

"Maybe it's got a bit to do with my hormones."

n This Wide Night, Tron Theatre, Glasgow, Thursday until March 15.