Timothy West and Prunella Scales embark on an epic adventure along one of the greatest achievements of British canal engineering. It's a world heritage site, and historically highly significant, yet very few people in this country have ever heard of the Rideau Canal. Heading 3000 miles from their London home, Tim and Pru arrive at Kingston, Canada, where the Rideau begins. Wending its way through the backwoods of Ontario, the Rideau links rivers and vast lakes to create a waterway that connects Lake Ontario with the city of Ottawa. Tim and Pru follow its 125-mile course, all the way to Canada's capital. En route, they take in Fort Henry; a lakeside resort; and navigate the famous Ottawa lock. They also discover the huge human cost of the canal's construction and meet with descendants of the Algonquin guides who helped with the build.