Today on Watercolour Challenge, Fern heads to ‘God's own country' — Yorkshire — to celebrate the golden age of steam railways. Four amateur artists set up their easels at a train station that's a movie star in its own right. Goathland station on the North York Moors is a heritage station on one of the oldest railway tracks in the world. But it's perhaps more famous as the Hogwarts Express station from the Harry Potter movies. Not only do the artists have to contend with painting the station, but there's a surprise guest in steam loco Peggy! Judging their paintings is internationally acclaimed army veteran-turned-painter Ady Wright. He gives some tips along the way, including a simple way of painting atmospheric steam using a palette knife and a cleansing wipe! As the artists get to grips with this historic and picturesque scene, Fern meets the stationmaster who began volunteering to keep the station alive in the 1960s. We also learn about the fashion of railway art through the work of one of the best there was — Yorkshireman Frank Mason, whose work inspired train journeys to Yorkshire's beauty spots. Will today's four painters be able to do the same?