This is one of those movies ("Jaws The Revenge" was another) that have a really low reputation, yet when you actually see them you find out that, while by no means good movies, they are at least passable time-fillers. Aside from Gert Frobe ("Goldfinger") being cast as a detective, there is nothing laughable about this - also nothing exceptional. The pacing is wrong; it doesn't stay focused on the mystery of the plot. But if you have two hours to waste...
