Ellen gets unexpectedly pregnant just after landing a big contract for her architects’ practice. She hopes to be away for the shortest time and hires Paula to cover the gap. As Paula shadows Ellen for the last months of her pregnancy, she at first seems the perfect hire – enthusiastic, personable, super-competent.

But Ellen soon begins to worry Paula has another agenda. Paula refuses to believe Ellen when she says she plans to return in a couple of months. She’s confident Ellen will change her mind when she falls in love with her baby. Ellen thinks that maybe Paula doesn’t want her back. Ever.

Earache’s glorious Neve Mcintosh plays Kay Gillies, an award-winning architect and role model for her profession. She’s always known what she wanted to do and it wasn’t children. She has a completely fulfilling job and marriage until her friend and colleague Ellen gets pregnant. She feels excluded from Ellen’s new life and fears her husband is becoming broody despite their agreement.

“The Replacement” starts on 28th February, 9pm, BBC1