The mustache has got to be real. Right? Everything else about Murder on the Orient Express—Kenneth Branagh’s stodgy, grandmother-friendly adaptation of Agatha Christie’s 1934 mystery novel—is so sumptuous that there’s no way they would skimp on such an obviously fake-looking mustache, not when it’s plastered to Branagh’s face so prominently. The cast is overstuffed with prestige, featuring a knight (Derek Jacobi), a Dame (Judi Dench), a Depp (Johnny), a Dafoe (Willem), a Daisy (Ridley), and a detective (the amazing and wonderful Olivia Colman). The sets are detailed and geographically consistent, the dramatic mountainous backdrop is computer-enhanced at great expense, and the 70mm camerawork is fancy-pants as all get out.

And yet Branagh’s mustache, a gratuitously frosted thing that emerges from his nose to bisect the entire front half of his skull, looks so absurd and unnatural that it takes you out of the movie every time the actor/director is onscreen. Which is a lot—he plays Christie’s renowned Belgian detective Hercule Poirot, who finds himself on a derailed train with a corpse, 12 suspects, and too many clues. There’s an overbearing tone of theatrically exaggerated artifice, which fits, because there’s no way to come out of Murder on the Orient Express without imagining it would make a much better play than movie.

As a star-studded actors’ showcase, Murder on the Orient Express is uncomfortable. As a mystery, it’s a total bust.

As movies go, it’s outright bad, even if you can forgive the mustache. Christie’s plot is ludicrous, of course—it’s one of her most far-fetched whodunnits—but it’s treated with a reverence that surgically removes any of her gimlet-eyed suspense. It’s easy to see why so many famous people eagerly signed up to play her outlandish, over-the-top characters, many of which get to reveal twisty-turny secrets. But all of the actors, from Michelle Pfeiffer to Penélope Cruz, seem completely at sea, bungling the stilted dialogue and never managing to behave like actual human beings. To make matters worse, the excessively talky script somehow gives each of them too little to do.

So as a star-studded actors’ showcase, Murder on the Orient Express is uncomfortable. As a mystery, it’s a total bust—you’ll care less about solving the murder than about figuring out just what is going on with Branagh’s mustache. No self-respecting makeup artist would let someone get in front of the camera looking that preposterous, right? Right?