A time traveler in military uniform wakes up on a sunny Berlin afternoon in 2011, looking up at a blue sky without enemy aircraft overhead. He hears no shelling, explosions or sirens. That the city still stands despite his orders that it be destroyed, right down to the screws and door handles, is something that puzzles him. “On the other hand, I am here too,” he thinks, “and I cannot understand that either.”

You know his name. You know his face. You know his hair and mustache, which are caricatured with sharp, witty minimalism on the cover of “Look Who’s Back,” in which a baffled Adolf Hitler is returned to the even more baffled German people. Now you’ll also know Timur Vermes, whose debut novel has created a sensation in Germany, been translated into many languages and generated endless essays asking whether it’s acceptable to laugh at Mr. Vermes’s Hitler jokes. Count on much more of this debate when the book’s May 5 publication date in the United States arrives.

There’d be no need to discuss the acceptability of laughter if “Look Who’s Back” weren’t desperately funny. But Mr. Vermes has created an ingenious comedy of errors in which the jokes are either on Hitler’s misapprehensions about the modern world or the modern world’s refusal to take him at face value. When he wakes up, the first people he meets are a group of boys at play. Are they members of the Hitler youth who just happen to be out of uniform? When one asks, “You all right, boss?,” he thinks the child’s failure to call him “Führer” is a minor slip. When he sees an abundance of Turkish newspapers at a kiosk, he can’t entertain the thought of a large immigrant population. Instead, he assumes that Turkey became the great ally that helped Germany win the war.

The man who runs the newsstand becomes the first benefactor of the indigent, confused new Hitler. And the shtick — perhaps not one of Hitler’s favorite words — that flies between them could come straight out of vaudeville. The news seller thinks that this Adolf Hitler, who never uses anything but his real name, must be some kind of performer. So, in slightly abbreviated form:

“Have you got your own program?”

“Naturally. I’ve had one since 1920.”

“Any fliers?”

“Don’t talk to me about the Luftwaffe. In the end they were a complete failure.”