Playwrights around the country must've shared a "Why didn't I think of that?" moment upon hearing the premise of John Longenbaugh's Sherlock Holmes and the Case of the Christmas Carol. The script combines the famously crotchety detective with a beloved-but-exhausted seasonal staple, and it will no doubt live forever on regional theater stages.

Longenbaugh's play neatly subs in Holmes (Michael Mendelson) for Ebenezer Scrooge; Watson (Todd Van Voris) for Bob Cratchit; and Holmes' nemesis, Moriarty (Tobias Andersen), for Jacob Marley. Since returning from self-imposed exile after killing Moriarty, Holmes has been living alone, uninterested in his cases and fixated on his chemistry experiments. He's grown cold toward Watson and his landlady (Vana O'Brien), and a falling out with Watson prompts a night of ghost-led self-reflection.

The Dickens/Doyle character mashups work well, even when it seems like they shouldn't—an early, funny scene when Moriarty's ghost visits Holmes is a highlight of the show, and a plot point in which Holmes accuses Watson of having financial motivations for their friendship is handled with surprising subtlety. Mendelson is satisfyingly caustic as the Scroogey Holmes—and while I preferred him before his crankiness was replaced by holiday cheer, even his rapid fluctuation from depression to holiday mania is in step with Doyle's literary creation.

The show has its flaws: Under Jon Kretzu's direction, actors race through the wordy script, but the show still feels long, thanks to a surfeit of plainly unnecessary plot points—Holmes' overcomplicated Christmas future includes a blatant cash-in on one of history's most notable outbreaks of holiday cheer, the spontaneous ceasefire shared by German and British forces in the trenches of World War I. A heartwarming story, to be sure, but tossing the specter of world war into this trifle clogs up an already overstuffed act and completely fails in its effort to elevate the stakes.

All told, though, the performances are solid (Van Voris, in particular, shines as Watson) and the script is clever—it's a more engaging and less schlocky show than audiences have any reason to expect this time of year.

Also, there is a robot. Just sayin'.