Agnes Brown has family troubles to contend with: her son Dermot has fallen out with Maria Nicholson, his long-term girlfriend, and Grandad is feeling poorly.

After a sleepless night, Mrs Brown decides to try to sort out Dermot and Maria's problem by giving Maria the benefit of her advice. But her heart-to-heart with Maria only succeeds in making the dispute worse. So Mrs Brown's daughter Cathy intervenes. She's a psychology student, and offers Dermot and Maria a counselling session. A dismayed Mrs Brown can't help interfering, and the session quickly descends into a blazing row between her and Cathy... with an effect on Dermot and Maria that not even Agnes Brown could have predicted.

Meanwhile, Grandad ends up in hospital when Dr Flynn's attempt to read his temperature goes dramatically wrong. And Cathy reveals the electrifying secret of how she keeps dodgy men at bay.

With Dermot and Maria's wedding just weeks away, the Brown household is in crisis.

Agnes Brown's son Dermot wants to ask his childhood friend Buster to be best man. But Agnes has set her heart on Mark Brown, her eldest son, being Dermot's best man. And Buster is a crook, of whom both the strong-willed Maria and Mrs Brown strongly disapprove.

On top of this, Mrs Brown's close friend and neighbour Winnie is distraught. Her husband Jacko has been rushed to hospital and cannot possibly afford to pay for the operation he urgently needs. And, needing cash for his wedding, Dermot has allowed himself to get embroiled in one of Buster's stupid- and dodgy - moneymaking scams.

It's time for Mrs Brown to exercise all her diplomatic skills, starting with 'accidentally' letting Maria know all about Dermot's best man decision.