The inviolable secret

A notorious burglar is momentarily released from prison to “test” a new type of safe. The burglary fails, and the bandit is taken back to his cell. During the night, however, he escapes and runs to take revenge with the safe that resisted him, after which he returns to his cell. Of the sensational heist an unsuspecting professor is accused by fortuitous circumstances, who would surely end up behind bars if the real burglar, meanwhile released, did not claim the honor of his deed.