A year ago, Mary Portas took on a seemingly impossible challenge: dragging the humble, forgotten, unloved charity shop into the 21st century. After five long months of toil and tears, she'd achieved a remarkable, lasting transformation, overhauling dismal donations and shocking stock and reinventing their dowdy stores.

But she's not finished yet. Six months later, she's returning to add the last piece to the jigsaw, with an idea to overhaul the loyal but ageing workforce and bring in a new breed of different, younger volunteer. First she must convince the current staff, then the charities themselves, before pushing on to find the new blood to fill 20 shop floors.

She embarks on a publicity drive across the capital - her OAP army faithfully alongside - culminating in a big hitting media event on Oxford Street. But with just a week to pull it off, it's a tough ask to fill the stores, persuade the nation's charities to permanently adopt her radical new ideas - and prove the sceptics wrong. Show less