The The Dutch Shoe Mystery (1931) follows Ellery Queen on yet another formulaic tale: The usual characters are all here, with the addition of embedded reporter Pete Harper. This is also another Depression-era mystery where a wealthy person is murdered for money.
Like The French Powder Mystery, Dutch Shoe has a closed off room, a secret laboratory set smack in the middle of a midtown hospital. This lab, however, is not the center of bustling activity. That is saved for the operating room, with enough seats for a crowded viewing.
One thing I find interesting about the layout of the book is with the interlude, when the Queens review the facts of the case. My copies of the previous Queen books are 1940s reprints, so I do not know if this was new to Dutch Shoe or not, but, the interlude is written with extra-wide margins, with an explanation that the reader can make use of the wide margins for marginalia, notes on what clues are important and such. Was this a one-time thing, or was it merely dropped, edited out, of future editions? My copy, which at one time was owned by Henry B. Green, has no notes written in the extra wide margins.
I’ve sometimes wondered why the wealthy so often are killed off in the popular fiction of the 1930s. On the one hand, the rich could be killed off to attract readers who wish they could do the same. On the other hand, perhaps it was a device to show readers an incredibly opulent world, so they could delight in dreaming of living within that sort of abundance. I’m sure others have analyzed that much more than I intend to.
What I also find interesting is how, well, bland the book is. While the story and plotting are good, they do not inspire. Ellery Queen had successfully written three popular detective novels, but left nothing for readers to really come back for. Later on, critic Anthony Boucher would famously declare, “Ellery Queen is the American detective story,” but for now, he was a nice mash-up of British crime fiction and Philo Vance. As it turned out, in order to advance creatively, the cousins would have to create another detective, a Shakespearean actor, of all things, to create what was to become “the American detective story.”
This was not to be an easy task. A few years earlier, in 1928, S.S. Van Dine, author of the Philo Vance mysteries, first published his infamous “Twenty Rules for Writing Detective Stories.” The room to move creatively was locked by these rules. Although Vance did identify tropes which had already become cliche (Rule #11 tells potential writers that, no, the butler must not have done it), there are several taboos which would be intriguing to break. For instance, Rule 9 reads:
There must be but one detective – that is, but one protagonist of deduction –
one deus ex machina. To bring the minds of three or four, or sometimes a
gang of detectives to bear on a problem, is not only to disperse the interest
and break the direct thread of logic, but to take an unfair advantage of the reader.
If there is more than one detective the reader doesn’t know who his codeductor is.
It’s like making the reader run a race with a relay team.
How refreshing it might be to have a detective story where, say, Marple, Holmes, Colombo and Fletcher (J.S., Irwin, or Jessica) all stumble over each other trying to solve a mystery, and coming up with different answers!
Dannay and Lee were not quite ready to break out of the locked rooms they had written around themselves, that comes several years down the line. However, beginning with they would at least try to redecorate the room.
Reading Ellery Queen 
There is a book where detective characters are spoofed. It is called Murder in Pastiche. Supposedly there is a Ellery Queen parody called Mallory King. Never read it. Someone told me that it parodies that 40s Ellery who is full of angst and guilt.
Zeno, can’t say I’ve ever run across that, but it sounds fantastic.
“Dutch Shoe” is the first tale in which Ellery can’t solve the mystery easily; he is missing something essential, and knows it, and when he finds it he bursts into one of his “eureka!” moments.
The other original thing at this point was the cousins’ choice of settings for their mysteries. Instead of a mansion with a library or other separate small place, we get a Broadway theatre in “Roman hat,” a department store in “French Powder,” and a hospital here. Later there is the indoor rodeo in “American Gun.” Ellery characterizes this as “suspects by the carload.”