Long, hot summer days bring farmers out into the fields in their droves. It's hay-making season, so Charlotte Smith and Adam Henson are in the thick of it, discovering what makes one of our oldest crops so special. Charlotte is put to work on the Lizard Peninsula in Cornwall by a farmer whose family have been making hay for over 500 years. She's never driven a modern tractor before, but gets the opportunity to learn from an experienced haymaker. Charlotte also gets the chance to see plenty of wildlife as the harvest activity attracts and excites myriad creatures; she is joined by an award-winning photographer who is taking advantage of the chance to take his next masterpiece. Adam is at a polo match, finding out how nutrients in high-end hay are helping horse owners to get ahead. But making perfect hay every time isn't easy when you're relying on the weather, as Simon from Highclere estate is finding this year.