The novel, narrated by the Englishman J., tells of a boat trip J. takes up with Thames River with his friends George and William Samuel Harris. His prose is rambling, and often digresses into anecdotes or long observational passages.
One night, the three men smoke together in J.'s London apartment, discussing their anxiety over their sicknesses. The reader can discern that they are actually hypochondriacs. After researching diseases at the British Museum, J. has recently concluded that he suffers from every disease known to man except for housemaid’s knee. The men decide that a vacation will be good for their health, and after some deliberating, they decide to spend a week rowing up the Thames with their dog, Montmorency.
There were four of us — George, and William Samuel Harris, and myself, and Montmorency. We were sitting in my room, smoking, and talking about how bad we were — bad from a medical point of view I mean, of course.
We were all feeling seedy, and we were getting quite nervous about it. Harris said he felt such extraordinary fits of giddiness come over him at times, that he hardly knew what he was doing; and then George said that he had fits of giddiness too, and hardly knew what he was doing. With me, it was my liver that was out of order. I knew it was my liver that was out of order, because I had just been reading a patent liver-pill circular, in which were detailed the various symptoms by which a man could tell when his liver was out of order. I had them all.