I freely admit to docking half a star from The Modern Scholar's Detective fiction from Victorian sleuths to the present because I'm miffed that some of my favorite authors and fictional sleuths were either left out or barely rated a mention. In the latter category is Rex Stout's Nero Wolfe. He's famous enough to rate an entry in The Dictionary of 20th Century Allusions. Here he's only part of a sentence listing classic examples of detectives with disabilities and a modern example is compared to him. Pfui!

We start out with the mysterious origins of detective fiction and end with trends in detective fiction. Professor Alexander points out that detective fiction adapts well to new forms of media and lists some examples.

Sherlock Holmes gets the biggest entry, of course. Hercule Poirot and Miss Marple also have substantial entries. (Professor Alexander mentions Agatha Christie appearing in the 2008 'Doctor Who' episode 'The Unicorn and the Wasp,' but not the homage to her called Agatha Grisley in the 1987 'The Real Ghosbusters' episode, 'Boo-Dunit'.)

We get to learn about some gifted amateurs, the Golden Age, professionals, hard-boiled detectives, police procedurals, espionage and techno-thrillers, lawyers, doctors, nurses, historical mysteries, female detectives (of the juveniles, only Nancy Drew is mentioned), international detectives, ethnic detectives, regional detectives, and disabled detectives.

The course guide includes photos of the main authors mentioned as well as cover art for some of their books and illustrations of some characters. There is a glossary, but I think the entry for 'Had I But Known' should mention that its description fits 'Romantic Suspense,' which is not an entry.

She does mention niche detective fiction in CD seven, but I'm afraid that science fiction, fantasy, and supernatural/paranormal detective fiction are left out unless you count a mention of Isaac Asimov. Although this came out in 2010, there's no mention of:

Kelley Armstrong's Women of Otherworld (featuring werewolves, vampires, half-demons, witches, ghosts, and a necromancer)
Patricia Briggs' series about Mercy Thompson, skinwalker
Lois McMaster Bujold's Miles Vorkosigan saga (which includes both investigations of murder and other crimes as well as espionage)
Butcher's Harry Dresden, Chicago's wizard detective, series
P. N. Elrod's noir Vampire Files series
Randall Garrett's Lord Darcy series set on an alternate earth where magic rules
Laurell K. Hamilton's Anita Blake (a necromancer) series and Merry Gentry (a fairy who is part human and part Brownie) series
Charlaine Harris' Southern Vampire mysteries
Kim Harrison's series about a witch named Rachel Morgan
Carolyn G. Hart's ghost detective, Bailey Ruth Raeburn
Tanya Huff's Blood series about a female detective and a vampire
Sir Terry Pratchett's Discworld City Watch novels. (Whether you're human, dwarf, troll, werewolf, goblin, golem, gnome, gargoyle, an Igor, Nac Mac Feegle, vampire, or zombie; Commander Sir Samuel Vimes will make sure you're a Copper through and through.)

Those are just examples I can think of off the top of my head if you're interested in pursuing those subgenres.

Indeed, the popular genre of cozy mysteries was pretty much dismissed in the section on classic mysteries. Prof. Alexander included several websites devoted to an author or a subgenre, but not one for cozies. Here's a link to the one I use: https://www.cozy-mystery.com/

No matter how annoyed I am at who got left out, the information provided was interesting. The list of authors and characters in the Common Knowledge section is by no means comprehensive, but will give you an idea about who's covered. ( )

The course has gotten me interested in the books I first read when Gail introduced me to detective fiction so long ago. I've paused the course after the first three classes and checked out from the public library the Agatha Christie and Edgar Allan Poe original mystery books and started reading them. I'll pick up the course after reading the Poe (The Dupin Stories), the first Mrs. Marple and the first Hercule Poirot books. But there is so much material everything is covered superficially. ( )