Last night’s episode of the ABC TV crime series Castle was the second of this season for the show, a program I’ve praised in the past. The most recent episodes of the series provide an object lesson in entertainment programming and especially for genre writers.

For those who haven’t seen the series, Castle is a semi-comical police procedural about a bestselling mystery author, Richard Castle, who gets himself partnered up with a beautiful female police detective in Manhattan to help solve crimes. The implausibility of the premise is no impediment to enjoyment of the show, as Nathan Fillion and Stana Katic are both a delight to watch as the central characters—their skill as performers is evident and easy to appreciate.

In addition, and even more importantly, the gaudy premise matches the show’s narrative style: it is a throwback to the great tradition of American surrealistic mysteries of the 1930s and ’40s. That’s a very important—and, alas, currently underappreciated—trend in mystery fiction exemplified by the writings of Ellery Queen (the truest master off the form), Fredric Brown, Anthony Boucher, Craig Rice, Hake Talbot, Joel Townsley Rogers, Herbert Brean, and the other great master of the form, John Dickson Carr. (And all of these writers owe a debt of gratitude to the earlier British crime fiction of G. K. Chesterton and the American Jacques Futrelle and a few others.)

What these and quite a few other writers of the time excelled at was creating a sense of wonder, building a fantastic situation that has an inexorable logic of its own. In their way they conveyed a sense of American life as a realm of astonishing possibilities ultimately grounded in common sense, logic, and morality. It’s a form of fiction I enjoy greatly and which I think has much to recommend it.

Castle is in that tradition. A typical episode will begin with a bizarre murder, and then progress to the investigation of a series of quirky or downright weird suspects and witnesses, and other additionally bizarre clues, while the two lead characters work out matters from their personal lives and their powerful but largely unacknowledged attraction toward each other. It’s great fun, although the events of the show are serious and often have important implications, which the writers do a good job of bringing out.

Last season’s finale cliffhanger, however, went in a more overtly suspenseful and “dark” direction, ending with Beckett, the female police detective, shot by a sniper as she spoke at her former boss’s funeral. It was much more like an episode of 24 than the Castleviewers had probably come to expect. And this season’s opening episode was much darker in tone than the show usually has been. As Beckett is recovering from her grave  injuries and the detectives investigate the attempt on her life, she and most of the other  major characters are upset with the normally happy-go-lucky writer Castle for various reasons. He, too, is down in the dumps, concerned about his failure to declare his love for Beckett when it could have made a difference in their lives.

All of this angst is very 1950s-Ellery Queen in approach, and that, alas was not a good decade for Queen.

There is also a new boss for Beckett and Castle, a police captain formerly from the Internal Affairs Division, who hates Castle and is so strict and surly that one could be forgiven for cringing whenever she appears on-screen. One amusing (and appealingly surrealistic) note arises, however: the new captain insists that her subordinates address her as “Sir.” That’s a very smart comment on modern life.

Although the cliffhanger episode and the season opener were interesting and quite watchable, neither played to the show’s strengths, it must be admitted.  Fortunately, last night’s episode marks a solid return to the show’s basic formula. The murders are committed by a costumed superhero who carries a samurai sword with which he cleaves a would-be rapist literally in half, from head to, well, groin.

That may sound very modern (in its spectacular grossness) to most ears, but in fact it’s the kind of thing one often finds in novels by Queen, S. S. Van Diane, and the like. Crazy but just barely possible, enough to keep you from throwing the book at the wall. (Well, enough to keep me from doing so, anyway.) And the scenes surrounding the murder in this Castle episode are handled without excessive gore and in fact rather comically—a sequence in the morgue shows two adjacent body bags holding the two halves of the body. Now that’s just funny.

Castle and his daughter also work out their problems, which had resulted in much bitterness on her part in the previous week’s episode. The episode also includes an interesting background in the world of comic book fiction, some fizzy dialogue between Castle and Beckett, and several goofy suspects with weird personalities and nutty motives.

In addition, it is revealed—though not to Castle—that Beckett was indeed still conscious when he told her he loved her as she lay presumably dying at the end of the previous season’s cliffhanger episode. It’s a very good plot development which holds promise for much irony and emotional dueling in future episodes.

So, what’s the lesson here for genre writers and genre fiction admirers? Just this: it’s all right to wander outside the boundaries once in a while, but the boundaries are there for a reason: because the conventions of any particular genre work. They come into being, after all, because people literally buy the narratives that take on that form. And I would posit that people like these narrative conventions because they speak the truth to them in a pleasing way.

Castle does that too—and that, I believe, is what makes it both popular and deserving of that popularity.