In this brand new series Mary Portas has changed sides. Rather than helping businesses to maximise profits, she's now championing the shopper, and battling to get Britain's biggest chains to put customers first.
Mary believes that Britain is cowering under a cloud of poor customer service and that we've never had it so bad.
By using the stealth weapon of secret shopping, she exposes shoddy customer service and uses the evidence to give company bosses a wake-up call.
And, with the help of her covert cameras, she's planning to start a retail revolution.
The giants may be delivering bumper profits but they won't be smiling for long - Mary and her gang of shoppers have caught some of Britain's biggest brands with their trousers down.
Together they have unearthed shoddy shop floors and minimal service from apathetic shop staff.
Having got to grips with the problems, Mary believes she's got the answer to this malaise.
Tagged in Mary Portas