Final film of Olga Augustová.
The first version of the screenplay, then called 'Morzakor', was written in 1950 and later rewritten and re-submitted several times. Martin Fric was meant to be director of the previous version and part of sir Hannibal Morris was already written with Oldrich Nový in mind.
The song "Námesícník" which sir Hannibal Morris Oldrich Nový listens to in a vault scene, was originally written and recorded for the older film Ctrnáctý u stolu (1943) co-directed by Nový and is sung by Nový himself.