No one, perhaps, but Arsène Lupin! For him, gates, walls and drawbridges did not exist. What use were the most formidable obstacles or the most careful precautions, if Arsène Lupin had decided to effect an entrance?

That evening, he wrote to the Procurer of the Republique at Rouen. He enclosed the threatening letter and solicited aid and protection.

The reply came at once to the effect that Arsène Lupin was in custody in the Prison de la Santé , under close surveillance, with no opportunity to write such a letter, which was, no doubt, the work of some imposter. But, as an act of precaution, the Procurer had submitted the letter to an expert in handwriting, who declared that, in spite of certain resemblances, the writing was not that of the prisoner.