Die Drei ??? (Fragezeichnen) is a long-standing program. It exists in audiobook form, young readers novels, of course in movies, and even in video games and has been in Germany since 1968. It was originally American, though, beginning in 1964 as The Three Investigators. I didn’t know about the American version until I started watching this 2009 film, which is dubbed from English. I looked again at the DVD and noticed there was no English option, a rare issue if the movie was originally filmed in English. Some of the actors are German and did the German synchronization. The company that produced it is Walt Disney Studios Motion Pictures Germany with a mostly-German team. It’s just unfortunate that they didn’t use German actors and the German language.
That being said, it’s a cute mystery for kids. A little pre-teen angst, a little suspense. It’s pretty much a live-action Scooby Doo without the talking dog. (Except there was actually an appearance of a talking dog… but not for very long.)