Taylor's popular backyard explorer and captivatingly shaggy blue dog manage to fall into another real adventure within the sunny domesticity of their rural neighborhood. As usual Henry's romantic fantasy (""The Orinoco River goes through very wild and dangerous territory. It goes right to the uncharted seas, I think"") is belied by Graham Booth's shimmering, tissuey scenes of bucolic serenity. Just the same, Henry and Angus do run adrift in a paddleless canoe, they do make shore on a tiny uninhabited island, and they do find buried treasure (some old bottles and cans). Then comes a rain storm (""Angus, things are serious. Maybe we will have to stay here all night""), followed after a suitably uncertain interval by a motorboat containing Henry's parents, who were guided to the spot by resourceful Henry's signal flags. Though veterans of Henry's two previous expeditions might recognize some familiar landmarks, that won't diminish their satisfaction in accompanying so intrepid and imaginative a voyager.