Lang's last movie, and certainly not his best, mostly due to conflicts with the producer. Also obviously the Germany of the 1930s was far different from that of 1960. Nonetheless, it is a fine film, with an excellent cast, only let down by an unexciting ending, one that would probably be barely up to par for a 70s cop show. The success of this film (and also the similar Edgar Wallace krimis that were attaining popularity at the same time) led to no less than five sequels, all of varying quality, but all quite enjoyable.

Note: The production schedule shows Carl Lange in the role of Hotelingenieur Lauber, but he must have been replaced prior to shooting.