If he no longer preserved the sentiment of self-preservation, he at least knew how to preserve the secret of his discovery.
Pavilion No.

17 was situated in the middle of a garden that was surrounded by hedges, and here Roch was accustomed to take exercise under the surveillance of his guardian.

This guardian lived in the same pavilion, slept in the same room with him, and kept constant watch upon him, never leaving him for an hour.

He hung upon the lightest words uttered by the patient in the course of his hallucinations, which generally occurred in the intermediary state between sleeping and waking--watched and listened while he dreamed.
This guardian was known as Gaydon.

Shortly after the sequestration of Thomas Roch, having learned that an attendant speaking French fluently was wanted, he had applied at Healthful House for the place, and had been engaged to look after the new inmate.
In reality the alleged Gaydon was a French engineer named Simon Hart, who for several years past had been connected with a manufactory of chemical products in New Jersey.