Cat's Paw: From his great Gothic mansion in Boston's Fenway, wealthy and elderly Martin Greenough rules as a mercurial despot over a curious menagerie of dependents that includes his determinedly respectable companion, Mrs. Warden, some rather odd servants, various nieces and nephews and their spouses and a male cat named Lucy. On the occasion of childless Cousin Mart's birthday, the vultures--or, in deference to the niceties, let us say the relatives--gather to demonstrate their devotion to the old man--though they are, in fact, much more interested in the old man's money. When it is learned that Cousin Mart is changing his will, however, the family's feathers are ruffled and the squawking begins!

After Cousin Mart's long burning candle is violently snuffed out during an evening of Fourth of July fireworks festivities, it falls to keen-minded Inspector Kane--accompanied, as usual, by his faithful chronicler, the prim attorney Mr. Underwood--to collar an individual who proves to have been a most clever killer indeed, even by the elevated standard of the ingenious Roger Scarlett.

Murder Among the Angells: The austere and forbidding abode of the Angells, located on Boston's Beacon Street, is a great L-shaped mansion curiously divided into two identical halves, which are respectively occupied by two aged brothers and their families and connected only by an elevator. The two Angell brothers, Carolus and Darius, have for decades been locked in a grim contest of survival in their divided mansion, on account of their eccentric health faddist father's queer will, which devises his entire estate to whichever brother outlives the other, as a way of encouraging the pair to live healthfully. Before the novel is over, however, both of the brothers will have died violently--one of them while traveling alone in the mansion elevator!

Thus is keen-minded Inspector Kane of the Boston police--who for the last recorded occasion is accompanied on a criminal investigation by his admiring friend Mr. Underwood, who happens to be Darius Angell's attorney--presented with what proves to be the strangest and most perplexing problem in homicide that the pair has encountered.