The Deceived cast discuss their characters on Lisa McGee's brand new thriller series

If you're anticipating Lisa McGee's latest foray into television, The Deceived, to have Derry Girls levels of uproarious humour, well – you've been deceived.

This new supernatural thriller – which will air its first two episodes this evening (September 7) on Virgin Media One – takes influence from classic thriller and horror stories like Daphne Du Maurier's Rebecca. It's an eerie tale of lust, mystery and intrigue, set against the rugged landscape of Donegal.

English student Ophelia (Emily Reid – Belgravia, Curfew), falls in love with her married lecturer (Emmett J. Scanlan – Peaky Blinders), and follows him from Cambridge to Donegal when he disappears from campus. It turns out their affair has been interrupted by a shocking and tragic death, and Ophelia finds herself trapped in a world where she can no longer trust her own mind. Hot Press sat down with Catherine Walker and Eleanor Methven – who play Roisin and Mary Mulvery, respectively – to discuss their roles and working with Lisa McGee.

"It's funny, someone says: 'the good news is you have a role in one of the biggest hit comedies in the last ten years, but the bad news is your character dies'," laughs Methven (who played Auntie Bridie in Derry Girls). "But of course, this is entirely different. At some points I feel Mary is very much like Mrs. Danvers. There are mirroring scenes, which I had great fun playing. Working with Lisa is great."

Methven plays Michael's overly suspicious mother-in-law. "She lives in a small village in Donegal, and she's quite forceful, controlling, and cares deeply about her daughter," Methven says. You could say she is the matriarchal figure of the series, although Methven hesitates to characterise Mary that way.

"I find that word fascinating. I think it's normally used in polite societies that are patriarchal, and I think the word 'matriarch' suggests the only place a woman can have true power is in the home," Methven says.

"I think Lisa wrote Mary as a powerful character in her own right, of her generation. She's had to operate through the world in a different way than Roisin has. Her power, to some extent, has come through Roisin, who may well be living the life that she wanted to. And I think for Mary's generation that's quite common. The Mrs. Danvers stuff is very clever, and you play it with a consciousness. There were layers upon layers of knowing what Mary knew...it's a really interesting thing as an actor, playing a character who is acting."

Roisin, Michael's wife, is played with understated excellence by Catherine Walker (Versailles, The Delinquent Season). An award-winning fiction writer, Roisin must walk an ever-thinning line between balancing her own success and her husband's giant ego. "I think her writing is quite feminist in form," Walker says. "Because you get to see the response young female students have when she walks into the room. She's much more successful than her husband, and Michael doesn't deal with that very well. There's a lot of jealousy. He manipulates her, he uses how attractive he is to younger women.

"Even though she is incredibly commercially successful, she isn't really accepted by academic and intellectual circles as much as she would like to be. Her background – and relationship with her mother – makes me think her success isn't built on very solid foundations, and Michael plays on that self-doubt."

How did Walker balance playing that self-doubt and success? "There's a brilliant line in the first episode, so cleverly written by Lisa and Tobias, where she says, 'I've just spent the last hour listening to some dreary old don explain my own work to me'", Walker recalls. "She can't have a conversation with a man unless he's explaining back to her what she does. I think this series explores that really well. Using a classic, film noir ghost story to highlight the extremity of how much we're dealing with that on a day-to-day basis is extremely smart.

"I think true power comes when you can sit in your vulnerability and your truth. Roisin has to play with masks all the time, as opposed to just being exactly who she is. She has to put forward an image of herself to the world, and be that image of the woman in the successful position, but inside, she doesn't feel that at all. I really identified with that. Interestingly, I have to play a lot of high-status characters, so I often feel that way."

• Watch The Deceived on Virgin Media One tonight at 9pm.