When Wolfe rejects the case as a family squabble, Lewent mentions that Beryl died of ptomaine poisoning at Huck's house; he believes that one of the three women murdered her.
The three employees Lewent suspects are secretary Dorothy Riff, nurse Sylvia Marcy, and housekeeper Cassie O'Shea.
Archie questions Huck, using the pretense that Beryl might have hinted at entrusting one of them with part of her father's estate to be turned over to Lewent, in an attempt to draw out information on them.
Inspector Cramer and his men soon arrive to question the household members; while this is going on, Archie suddenly realizes that he knows how Lewent's body was transported without attracting attention.
Wolfe identifies Huck as the murderer and explains that he tricked Lewent into bending over to pick something up off the floor, then struck him with a spherical paperweight.
He was eager to accept Wolfe's $100,000 offer because he knew that Lewent would never hear of the results, and he had earlier poisoned Beryl in order to inherit her fortune.