Ming-Na Wen has returned to network television as Melinda May in Joss Whedon’s Agents of S.H.I.E.L.D. Disappointing, badly written first season, unfortunately, and for those of us who remember her wonderful breakthrough in “The Joy Luck,” it is sad to see her reduced to the Hollywood you’re an Asian Woman, so you can be the kick-ass martial arts chick syndrome. Mind you, she can at 51 wear the catsuit Diana Rigg wore at 24 in a much different “Avengers,” as well as carry through fight scenes that Rigg never could, so props to her, but she’s woefully underused.

Seeing Ms. Wen invariably reminds me of a conversation I had with my mystery writer buddy S. J. Rozan at some Bouchercon several years back. She was talking about how she would cast her series featuring Lydia Chin and Bill Smith [read them if you haven’t], and Wen’s name came up. Wen would have been good had it been done then. The time lapse since that conversation has taken her out of contention. Lydia Chin is, of course, a Chinese-American detective with some serious martial arts chops, but those are rarely deployed — the detecting is the thing.

It’s fun to mentally cast one’s characters, and I wonder how often the actors selected match the writer’s intent. Colin Dexter loved John Thaw’s portrayal of Inspector Morse, and the books that came out after the BBC series began seemed to reflect the actor more and more. On the other hand, the fans may have their own idea of a character in mind. There was a huge brouhaha when Tom Cruise was cast as Jack Reacher. “Reacher is tall! Cruise is not!” screamed the fans, forgetting that Cruise not only is a damn good actor, but also possesses the most credible physicality in fight scenes of any major Hollywood star. I’m sure that Lee Child’s reaction to the casting was along the lines of “I like people who are going to make me money.” [The movie underperformed, but a sequel is in the works.]

A question writers often get is, “Who would you cast in the movie of your book?” This sends us into reveries of endorsing checks with large numbers to the right of and beneath our names, walking down red carpets in tuxes, appearing on national talk shows while trying to appear modest and witty, yet self-deprecating. The truth is, unless you are also the executive producer, you, the writer, will have no control over any part of what happens once you sign away the rights. And you agree to this because the first part of the fantasy, that large-dollar amount check, overwhelms everything else.

I have nothing against this process. [It’s only happened to me once, with a short story that came thisclose to being made, with a screenplay by an Oscar-winner and another Oscar-winner lined up to star. Fortunately, I didn’t spend the money I didn’t get before I got it, which I didn’t. Long story for a short story.]

As to who I would cast — I try not to think about it. I’m writing characters who need to come to life on the page, as opposed to barely fleshed-out movie proposals disguised as a novel. I tend to underdescribe them, which might be a fault, but I prefer to give a bare bones description and let the readers flesh out the rest with their imaginations. There will be bits and pieces — Theophilos, my jester, is tall, skinny and flexible enough for tumbling and acrobatics, but we don’t know much more. His age wasn’t pinned down precisely until the fifth book, An Antic Disposition, which was his origins book. Claudia, née Viola, is given a little more since we see her through his eyes, but not much.

Did I play the casting game with them? Yes, of course. I had the movie fantasies like anyone would. But these characters started forming in the mid-Nineties. The actors I would have cast then? A tall actor with a good singing voice who was adept at physical comedy — Kevin Kline leapt to mind, and if the movie had been made immediately, he would have been great. But he’s 66 now. For Viola at that time, I needed a woman who was a chameleon, short and thirty-ish. I was a big fan of Jennifer Jason Leigh. Still am, but she’s 53.

Even if Hollywood buys the rights, it takes years to get anything actually made, and therein lies the problem. So, if anyone comes knocking, I’ll sign away my characters with alacrity. [Maybe I can get them to let me write the screenplay — nah, who am I kidding?] And I’ll hope to God they get it right. Or make it better. As much as I loved Baum’s Oz books, I’m glad that MGM made Dorothy old enough to be played by Judy Garland. It would have been a much poorer movie if she had been the age depicted in the original Denslow illustration.

And I’m a patient man. Matt Smith isn’t old enough to play Theophilos yet. But he will be. And I hear he can sing.