In the Middle Ages, mules were used to transport goods across Britain. Strong, sturdy and able to carry a good 160lbs of weight, they made ideal walking companions - as long as you didn't ask them to do anything they didn't want to do! So when Hugh Thomson decides he wants to revive this ancient tradition, but with a mule who is only willing to carry sandwiches, water and a map, his father can't quite comprehend why: "Taking a mule across England? Really? Whatever for?" Using old drovers' roads that have largely passed into disrepair, Hugh and his trusty mule Jethro set out to travel across England, from the Lake District to the Yorkshire Moors. Along the way, they discover a landscape rich in history, and encounter the charismatic people who bring it to life.