Who knew taking maternity leave could prove so treacherous? Architect Ellen learns the hard way in new BBC drama The Replacement, but who plays her?

And why do her work colleagues look so familiar?

Meet the cast and characters of The Replacement...

Ellen – Morven Christie 

Ellen is a successful architect who gets pregnant just as her career is about to take off. She’s not worried though, believing it won’t take her long to get back to work

From Grantchester to The A Word and BBC comedy Twenty Twelve, you’ve seen a LOT of Morven Christie on your TV screen of late. The Scottish actress also popped up in Doctor Who, in series nine episode Under The Lake.

Paula – Vicky McClure

Paula was a prodigy when she started out as an architect but stopped work to raise her daughter. Now Caris is 10, she feels ready to pick up where she left off.

McClure is probably best known for her BAFTA-winning turn as Lol in Shane Meadows’ This Is England, her role as policewoman Kate Fleming in Line of Duty and and her spell as a no-nonsense national reporter in Broadchurch. Most recently you’ll have spotted her in The Secret Agent, a thrilling three-part drama about anarchy and terrorism in Victorian London.

Ian – Richard Rankin

Ian's thrilled at the prospect of becoming a father but can't switch off his psychiatrist's judgement. He met Ellen as a patient and has always struggled with boundaries when it comes to her. 

Fans of BBC3's Thirteen will recognise Rankin as DI Elliott Carne, but you’ll also know him as Captain Thomas Gillan from The Crimson Field and as a star of Scotland’s own Burnistoun. Rankin’s also had roles in Silent Witness, The Syndicate and From Darkness, and recently joined the cast of Outlander in the role of Roger Wakefield.