Paul explores the river Annan in Dumfries and Galloway, following it from where it rises above the Devil's Beef Tub all the way to the Solway Firth. On the way he samples some dubious-smelling 'healthy' spa water, hears disturbing evidence that Robert the Bruce may have been an Essex boy and discovers the explosive devil's porridge before following in the footsteps of Robert Burns by taking a dunk in the briny close to where the river meets the sea.