Le manoir du diable ending explained

What happens

One of the cavaliers holds up a crucifix. The ghosts, skeletons and witches shrink back, the devil's power fails, and he vanishes. The castle is safe again, and the whole nightmare ends in one clean stroke.

The last image

The crucifix is raised and the devil is gone, leaving the cavaliers standing in the empty hall.

What it says

The ending is a simple moral reversal: faith beats the supernatural, as it did on the melodrama stage. But the film's real point is the show itself. It stops once the tricks are spent and you have had your wonder.