Gregg Wallace returns to lift the lid on the science behind how the supermarkets bring us our food. He is joined by journalist Babita Sharma as together they discover the impact the fiercest supermarket wars in history are having on the food in our shopping trolleys. In this episode, Gregg discovers the high-tech acoustic testing Asda are using to get an edge in the battle to bring us a perfect avocado, and he gets a lesson in social media by tormenting his taste buds with the world's hottest chilli. Meanwhile, Babita uncovers the intelligence gatherers who know more about what we buy - and why - than we do.

Gregg and Babita look at one of the fastest-growing battlegrounds - convenience. Gregg finds out what it takes to bring us the easiest ever fish and discovers how supermarkets decide where to open convenience stores. Babita travels to Spain on the trail of our favourite convenience fruit - the easy peeler.