The "All I need to know..." might be a bit of a dated cliche and an unnecessary one at that. Maybe Graham felt he needed the rhetorical device to help organize his writing but I doubt that the reader will come away with a conviction in, or the necessity for, the title phrase.
It simply isnt necessary for the reader.
What we get here is better termed an Appreciation. Graham takes through seven of the all-time mystery greats, considering and enjoying their body of work like you might hold a tawny port in your mouth savoring it. As the author says in his introduction "to read Nero Wolfe, or to watch an episode of Columbo or Monk, is to take a journey with an old friend."
Sherlock Holmes, Nero Wolfe, Father Brown, Dan Holiday- you cant even name check these characters with engendering a warm smile in most mystery readers. And Graham goes far past a name check or just a mere recitation of dry facts of books sold, total cases, etc. He has an appreciation for each of these detectives and a great knowledge of their 'careers' in all media. Adam is able to cite their various appearance on radio, movies and tv. I think Graham is right that despite being essayed by Sidney Greenstreet, William Conrad and Maury Chaykin we still havent seen a "most satisfactory" portrayal of the most enigmatically drawn Nero Wolfe.
The essays that stand out the most for me are probably Wolfe and Father Brown. Bantam reissued about 50 Wolfe books a decade ago and included in each was a introduction by another detective on the Stout and his character- so Graham has waded into a field that already has several dozen entries by mystery professionals. Graham more than holds his own in this company- and in discussing "And be a Villain" and "Instead of Evidence" he not only offers the reader some excellent insights, he prompts excitement at the thought of reading, or re-reading our old friend, as irascible and confounding as he may be.
The discussion of Father Brown contains references to a BBC radio series I didnt know existed and am quite interested in tracking down, although I did know about Mutual's radio show. Graham also includes the Fr. Brown short story "The Three Tools of Death" in this digital book and I am sure that any modern reader is likely to be quite taken aback by the reason behind the story's death. There is a British Father Brown series from the early '70 that is streaming on NetFlix and it is quite enjoyable to compare the characterization of the victim to the description in the story. When I first saw the show I thought the actor was playing it far too broad, but in reading the story now I find Chesterton's description drawing be back unavoidably to that portrayal.
In short this digital book is like meeting old friends and taking an enjoyable trip with them. Laugh at their faults, thrill in their successes, remember all over again, and pick up a hint or two to another great book or show to track down and enjoy. And waiting in patient hope for the day when Nero and Archie get the due on the screen.
Graham has both a knowledge, reverence and appreciation of his subject matter. If this is a seed for a longer work in this field by him that would be welcome news to all mystery fans.
At $1.99 I am sure that all but the most encyclopedic mystery fans will feel that have received their money's worth. Even great readers in the genre are unlikely to have the radio knowledge that Graham has.
And since the book is free on Prime if you are interested in classic mysteries this is a no-brainer purchase.