The Water Strider

A homeless man who goes by the nickname of Vermont was found stabbed in the courtyard of the Gellert's mansion. It is soon discovered that Vermont had recently moved in with the wealthy family, on the insistence of Lambert Gellert, the youngest son.
As a favor to the detective in charge of the investigation, Oscar Lance, philanthropist and part-time sleuth, looks into the strange case. Aided by Harleth St. Cyr, his personal assistant, Lance pieces together Vermont's story, and grows more and more sympathetic of the dead man because the latter was genuinely good towards others.
But who killed him? Will the answer to this crime be found among his homeless friends, or inside the mansion?