Millionaire Nathaniel Bancroft is going to sit for his portrait, and a committee has been formed to select a painter for the lucrative commission. The committee consists of Nathaniel's daughter Eleanor Bancroft, lawyer Justin Leonard, and art critic Mark Mason. The painters being considered are traditionalist Ellis Kane, modernist Ann Murdock, and bohemian "Pinky" St. Clair. At a gathering at Kane's studio, the principals are seated (mostly) at a round table, looking over Kane's collection of miniature paintings: Suddenly Mason cries out that someone has stepped on his foot, although no one saw this happen. He turns ill immediately and soon is dead. There is no apparent cause, but an autopsy shows poisoning by strophanthin, a cardiac stimulant.