A historical mystery of sorts, although it reads much more like a straight historical novel with a strong mystery element than a genre mystery.
At the turn of the century, a suicidally depressed biochemist by the name of Reisden bumps into an old man who addresses him by a name Reisden doesn't recognize; later, he is approached and asked to impersonate a long-since-vanished child in order to straighten out a complicated situation in which the fact that the child heir is neither present nor legally dead has stuck an entire family in legal, financial, and emotional limbo. Reisden agrees, but once he arrives and becomes entangled in the family affairs he learns that he might actually be that vanished child; but if so, why doesn't he remember his past, as the child was nine when he disappeared, and if not, will Reisden's presence flush out the murderer?
The book is extremely well-written and well-characterized. A plotline involving a near-blind female pianist is so much better and less sappy than I expected it to be when it was introduced that I was shocked, and I really felt for the characters. The period details involving Reisden's work, early forensics, education for the blind, and lots more are all interesting, thoroughly integrated into the story, and essential to the plot and themes. A terrific book. It has two sequels, which I haven't read yet. Spoil me for major plot developments in those and die.