Puzzles of the Black Widowers

The Black Widowers meet once a month at the Milano Restaurant (notice that they take the task of host in rotation). Each month the host brings a guest for grilling, beginning with the question `How do you justify your existence?' and ending with ferreting out some mystery to be solved. The seventh Black Widower - Henry, the waiter - always solves the problem after the other six have cleared the ground a bit. The problem often isn't a crime - just some little puzzle that's been driving the guest crazy. This volume has an unusual number of spy stories, though.I personally find the by-play between the Black Widowers entertaining in itself. For instance, Rubin can be counted upon to severely libel another writer of his acquaintance, one Isaac Asimov, a few times in every volume. :)"The Fourth Homonym" - Host: Trumbull. Guest: Nicholas Brant, lawyer. A long-ago client named one of his children to head the family business with his dying breath - but only the word 'to' could be understood."Unique Is Where You Find It" - Host: Rubin. Guest: Horace Rubin, Rubin's nephew, a doctoral candidate in chemistry who has been issued a challenge by a hostile member of his committee: "I'm thinking of the name of a unique element.""The Lucky Piece" - Host: Drake. Guest: Albert Silverstein, novelty store owner. A boy lost his lucky piece in a resort sitting-room - where it vanished into thin air."Triple Devil" - Host: Gonzalo. Guest: Benjamin Manfred, self-made man. Manfred had inherited a single book of his choosing from the old man's library, with only an enigmatic phrase as a clue to the correct choice."Sunset on the Water" - Host: Avalon. Guest: Chester Dunhill, a historian whose heart's desire is to own _The Historians' History of the World_. Someone has finally answered his advertisement, offering a copy for sale - but Dunhill threw the envelope away, so the only remaining clue to the writer's address is the text of the letter itself."Where Is He?" - Host: Halsted. Guest: Bradford Hume, after-dinner speaker. Hume was hired for a taping session - but the cameraman, 'Old Reliable', didn't appear."The Old Purse" - Host: Trumbull. Guest: William Teller. Why was his wife's old purse stolen, only for all the contents to be returned anonymously, without the purse itself?"The Quiet Place" - Host: Rubin. Guest: Theodore Jarvik, Rubin's editor. The only clue Jarvik had to the identity of the man he met at the quiet resort was that he used the nom de guerre 'Dark Horse'."The Four-Leaf Clover" - Host: Drake. Guest: Alexander Mountjoy, college president. Several faculty members were taken hostage recently by terrorists, and one of them betrayed a fellow hostage (a spy). The spy left one enigmatic clue to the identity of the traitor..."The Envelope" - Host: Gonzalo. Guest: Francis MacShannon, one-time collector of postmarks, which once led to his part in the capture of a spy."The Alibi" - Host: Avalon. Guest: Leonard Koenig, retired from counterintelligence. How did Koenig fi