Mason is guiding Goliath, an ancient tractor engine, to Bernie's garage - but he ends up causing traffic chaos when the engine breaks down in the middle of the road. Eva and James Knight approach the road diversion manned by Pc Younger, but when the brakes fail on their van, the couple swerve into a ditch. When Eva refuses to go to hospital for her injuries, Carol gives the couple a lift home to Holly Cottage. Inviting Carol in, Eva and James are stunned to discover that their pottery studio has been broken into, and there's graffiti and a swastika painted on the wall. Carol calls the police - but Eva and James clearly don't want them involved. Arriving at Holly Cottage, Mason reads the graffiti and James translates the German words used. Unsure of the connection, Eva tells Mason that she's Jewish, and admits that another break-in occurred recently. Could the attack be racially motivated? And can Mason get to the bottom of things before more serious damage is done? Also, David manages to fix Goliath and agrees to take it for a test run. But he gets a shock when the handle comes off in his hand and Goliath goes hurtling across the field. Can David beat Goliath and stop the runaway engine?
