At seventeen, Ashita watched her father die behind a fever chart that said "unknown origin." Years later, a DM fellow on a crowded rheumatology ward, she has made a private rule of refusing the phrase. Seventeen cases take her from a tailor who cannot hold a needle to a watchmaker who cannot hold his tweezers, from a village health centre to Berlin, London, Geneva, Bethesda and Tokyo. Part detective story, part ward diary, part teaching text.