The long history of these Canadian forebears is lovingly reconstructed, in often inordinate detail, and it’s only when Paul Theroux himself crosses the border that the book’s pace picks up ... Isn’t a flattering one-note narrative of Canadian valor ... Theroux, for his part, is usually charming, even when he’s cranky, and even when acting the braggy American, recalling instances of Canadians telling him how much they love his work.