Dotted along the entire length of the canal there are villages and hamlets. It is said that most have been sites of human settlements for thousands of years, which is a bit perplexing, as the canal itself was only dug two centuries ago. The hospital barge plies up and down the canal constantly, turning when it gets to Mudberth and heading straight back to Muckfield, never stopping except at locks. There are many locks. When a villager or hamleteer is sick, they are carted to the canalside by their neighbours and hauled aboard the hospital barge by a steam-powered crane-and-stretcher-and-pincer contraption. Once they have been cured, if they are cured, they are dumped ashore at the next village or hamlet, and have to make their own way home by land, unless, as is common, they choose to remain in the village or hamlet where they have been dumped, and thus do the canalside communities intermingle.

The hospital barge is staffed by a gaggle of homeopaths and healers and fraudsters and quacks, and the dispensary holds shelf after shelf packed with pointless potions such as Bach flower remedies and Beethoven weed remedies and Bruckner nettle remedies. There is not a single bottle of Baxter’s Sour But Invigorating Syrup to be found, let alone any cranial integument soothers or antibiotics. It is a wonder that any of the patients are ever cured, but in fairness it must be said that those dumped ashore at a village or hamlet miles up or down the canal from where they were winched aboard the barge show remarkable perkiness, and in many cases appear to be immortal. In the village of Filthwick, for example, no one has died in the last sixty years, and the gymnasium is filled with sprightly one-hundred-and-fifty-year-olds jumping about and springing and bounding and hopping and somersaulting and otherwise engaging in decidedly energetic calisthenics.

This being the canal along the towpath of which Dobson often trudged, the out of print pamphleteer could hardly resist writing about the hospital barge. But he wanted more than the view of a disinterested observer, and waited to fall sick so he could go aboard the barge as a patient. Alas, Dobson had the constitution of a large, sinewy, more or less rectangular animal with no known predators, and never suffered illness. He became impatient, standing on the canal towpath watching the hospital barge pass him by, occasionally witnessing the winching on of an agued wreck or the dumping of a revivified Pointy Towner. Eventually, the pamphleteer could wait no longer, and he took the fateful step of injecting himself with an experimental serum concocted by one of his pals down at the Cow & Pins. The fizzing hissing dapple-dun fluid smelled of rust and blood oranges, and was meant to cause harmless shuddering with all the appearance of a death rattle. In Dobson it had an alarmingly different effect, in that it provoked a mental imbalance making him petrified of boats and ships and yachts and barges, so much so that at the sight of water, even of a duckpond, he ran away screaming.

A fortnight later, when the serum wore off, Dobson learned through an article in the Canalside Gazette that the hospital barge had been rendered invisible. It, and its crew of homeopaths and healers and fraudsters and quacks, and its on-board patients, were never seen again, and nor were the many, many dead who had never been cured upon the barge, and whose final resting places are an unutterable mystery.