Mum is having one of Polka Dot days. Like Freda the Volvo, sometimes Mum needs a bit of a tune-up. Usually, one day in bed does the job. But it's been three days already and Mum's not getting any better. And the Leonard men are starting to worry. Phillip has been wetting the bed, Sarge is putting on a brave face but Lockie can tell he's concerned and Lockie himself has come over all mature and responsible, taking on the housework and cooking duties. With so much going on at home, Lockie has decided to also be mature and responsible about his and Vicki's break-up... if he can just get his head around the definition of those two words. As the pressure gets too much for Lockie, he feels compelled to do something totally irresponsible and immature. Can he resist the bone-crunching allure of skate-boarding down notorious Zig Zag Hill?