Homicide Trinity is a collection of Nero Wolfe mystery novellas by Rex Stout, published by the Viking Press in 1962. The book comprises three stories:

"Eeny Meeny Murder Mo", first published in Ellery Queen's Mystery Magazine #220 (March 1962)
"Death of a Demon", first serialized in three issues of The Saturday Evening Post (June 10, 17 and 24, 1961)
"Counterfeit for Murder", first serialized as "The Counterfeiter's Knife" in three issues of The Saturday Evening Post (January 14, 21 and 28, 1961) (Wikipedia).
"It’s a wily killer who dares to strike on Nero Wolfe’s hallowed turf—and leave a corpse strangled with Wolfe’s own soup-stained tie. But no sooner does the gourmandizing sleuth clean up this first course of murder than he faces a gun-toting wife who serves up a confession of homicidal intent—only to become the sole suspect when the corpus delicti is found. It’s murder à la carte when the third course is served: a cop-hating landlady brings Wolfe counterfeit cash—that leads to genuine murder. It’s up to Wolfe to see that the malefactors get their just deserts. " Amazon.