Mary Portas embarks on a mission to transform the charity shop sector, starting with one of Save the Children’s worst-performing stores in Orpington, Kent. To understand the challenges, she rolls up her sleeves and works alongside the mostly retired volunteer staff. Shocked by the poor quality of donations, Mary leads a bold stunt at a London shopping center to highlight the issue. Back in Orpington, she launches a campaign to improve donation quality, but her efforts face resistance, leaving Mary questioning if she’s taken on too much.

Mary Portas continues her mission to prove charity shops can thrive on the high street. She opens a retail academy in London to teach volunteers how to boost profits, but her bold ideas face pushback. At her Orpington shop, Mary secures funding for a £15,000 shopfit and hires a manager, but her changes spark tension among long-serving volunteers. As the relaunch nears, Mary begins to wonder if her ambitious plans have gone too far.

Mary enters the final stretch of her campaign with just four weeks to prove her ideas can transform charity shops. At London Fashion Week, she and her volunteers convince celebrities and fashion editors to showcase charity shop finds, grabbing media attention. She launches “D-Day,” a donation drive involving multiple charities, and rebrands her Orpington shop as the Living and Giving Shop, offering local designers a 50/50 profit split. With tensions rising among her volunteers, Mary pushes to unite the team. After five months, she meets with Save the Children to reveal if her reforms hit the £2,000-a-week target and if her vision will be adopted chain-wide.