In “The Tourist,” Johnny Depp is asked to play a bland American everyman, in the fashion of Cary Grant in “North by Northwest” or Jimmy Stewart in “The Man Who Knew Too Much.” That’s a bit like asking Michael Bolton to play death metal or Jackson Pollock to paint inside the lines. Depp adopts an affected, unplaceable accent and contorts his face into whimsical-weirdo expressions — the same ones he’s been using since “Benny and Joon.”

It’s a spectacularly misconceived performance, and what’s remarkable about “The Tourist” is that Depp’s not even the worst thing about the movie. That honor goes to Angelina Jolie, who adopts her own affected accent (a kind of Madonna-ese British) and struts through the proceedings with an imperious stare that closes off all the other performers. Her Elise Clifton-Ward is supposed to be a madly romantic woman who falls in love all the time, but clearly the only one Jolie is in love with here is herself.

Directed by Florian Henckel von Donnersmarck, taking a radical step backward from his Oscar-winning debut “The Lives of Others,” “The Tourist” illustrates what happens when you cast two giant, self-orbiting stars and then are either too intimidated or too confused to actually direct them.

For what it’s worth, the story is a silly spinoff of Hitchcock’s “wrong man” thrillers. Elise is wanted for her connection to a thief named Alexander Pierce. On a train to Venice, she chooses a seemingly innocent American tourist — Depp’s Frank Tupelo — and fools her pursuers into thinking he’s Pierce.

But there’s little to care about in the end, and the action is all ineptly staged. The movie sputters to a conclusion so predictable you first feel embarrassed for all involved, until your embarrassment turns to indignation: How stupid does Hollywood believe audiences to be if they think they can put a turkey like “The Tourist” over on us?