Synopsis: Dr. Halidonhill is consulted by a sickly man who he thinks is incurable. But he wants to test the rumored curative powers of watercress, so he tells the man to eat nothing else for six months. At the end of that time the patient returns bursting with health. Amazed, the doctor shots him dead so that he can do an autopsy and try to figure out how the watercress cure works. On trial for murder, he is sure to be acquitted, because he did it for the progress of knowledge: "...the exclusive love of the humanity of the future without any regard for the individual of the present is, in our own time, the only sole motive that ought to justify the acquittal under any circumstances, of the magnanimous extremists of science."