Four stories in the collection feature the character of Wendell Urth, who is a leading extra-terrologist (an expert on alien worlds and life originating on them). Urth is eccentric in that he has a phobia of all mechanical forms of transport (an exaggeration of Asimov's own aversion to flying) but they all have one common feature: detective mysteries showing Asimov theory that science fiction is a literary genre but it can develop into all the popular genres: romantic, western, adventure, terror,... anyone and all of them.
As for this collection, is well known Asimov's passion for detective stories, he never tired of proclaiming his admiration for Agatha Christie, and these stories are selected because they are markedly police & criminal stories, detective stories full of mystery. Most are not convoluted stories, they are not full of red herrings or lacking information, and follow the same general pattern: Asimov raises the mystery or problem -that is clearly stated in the first half- and in the second half the solution is given without further artifice.
- "The Singing Bell" (1954, a Wendell Urth story)
- "The Talking Stone" (1955, a Wendell Urth story)
- "What's in a Name?" (1956)
- "The Dying Night" (1956, a Wendell Urth story)
- "Pâté de Foie Gras" (1956)
- "The Dust of Death" (1957)
- "A Loint of Paw" (1957)
- "I'm in Marsport Without Hilda" (1957)
- "Marooned Off Vesta" (1939)
- "Anniversary" (1959, a Multivac story)
- "Obituary" (1959)
- "Star Light" (1962)
- "The Key" (1966, a Wendell Urth story)
- "The Billiard Ball" (1967)

Asimov has always been accused of being a misogynist (women characters are the exception in his work) and prudish. About "I'm in Marsport without Hisda, he says that attempted to pull off that sanbenito, or at least show that he was able to write something "spicy" (and, in my opinion, he failed miserably cause spicy, spicy... he's really prudish, Asimov :)))
But these are very funny stories followed by notes where the author explaines how sometimes science has rendered obsolete or disproved parts of them but he still did not want to change the story because of something as unimportant as reality.