Ironic moustaches are so weirdly popular now that they made an entire movie about them. Some cinematic genius somewhere, figuring that people already buy moustache-themed tee shirts, Band-Aids, beer huggers, necklaces, trucker hats, boxer shorts, air fresheners and cell phone cases, that literally the only thing missing from this marketing bonanza was what could be generously described as a “film” about a funny moustache.

I feel “Mortdecai” went into production on the sole premise of “Johnny Depp wears a silly moustache,” and people thought the poster would look funny, and at some point someone realized they needed a script. Or possibly not. When someone did put something on paper, it was as thin a conceit as you could ever ask for, like one of the lame “Saturday Night Live” sketches where even the participants can feel it tanking but have to at least finish it up so the show won’t run short.

Johnny Depp is uncharacteristically unlikeable as a bankrupt art dealer brought in on an investigation of national importance.

Johnny Depp is uncharacteristically unlikeable as a bankrupt art dealer brought in on an investigation of national importance.

Imagine my surprise when at the end of the credits I saw this thing was allegedly based on a novel. Further research reveals there is an entire series of Mortdecai novels written in the 1970s by Kyril Bonfiglioli, darkly comic satires of a preening, misogynistic art dealer and his adventures. Apparently they have a cult following.

That’s not going to happen to this movie, I fear, and I also don’t see a series in the future. It certainly didn’t leave me wanting more. But here’s the plot, since I sat through the thing just to satisfy my curiosity because, God help me, I guess I was intrigued by that stupid poster. They got me!

Johnny Depp plays a morally and financially bankrupt art dealer who is brought in on an investigation of national importance. Upright investigator Ewan McGregor brings in his old school chum and romantic rival Mortdecai because he’s a shady insider in the world of stolen art, and because he’s still in love with Lady Mortdecai, played by Gwyneth Paltrow. With the help of his humorously dedicated manservant (Paul Bettany), they basically run around looking for the painting so they can get the reward and pay off their back taxes.

I realize it’s popular (and appropriate) to excoriate the once-edgy and talented, now overexposed and maybe still talented, Depp. What was a pleasant, amusing surprise in the first “Pirates of the Caribbean” is now an annoying compulsion of excessive quirkiness and too much man jewelry.

However, this crappy movie was not entirely Depp’s fault. The shabby mechanics of “Mortdecai” as a whole are worse than his individual performance. That’s bad too, but the movie itself is so poorly written that I don’t see how anyone could’ve made that character any better. It’s hard to believe the writer had an entire series of novels from which to pull, yet ended up with something so utterly flimsy, and simply unfunny.

For example, there is a running gag that Mortdecai’s moustache makes his wife gag. That’s just lame, and they do it repeatedly. More than once scene centers entirely around that concept alone. There is no accent on earth funny enough to make those lines clever.

The reason it seems like Depp’s fault is that the entire burden of a completely empty script was riding on audience goodwill toward him. Someone miscalculated. Instead of expecting Depp to simply materialize a memorable character out of thin air, someone somewhere should have written down something clever or interesting for him to say, or to do, at some point in this film. Facial hair, however funny it may look, does not a feature film make.