they must have proofs.

There aren't any--or rather, what there are, I've got!" He pointed to a small safe let into the wall.

"In that safe are the coronet, and, above all, the death certificate of the Duke of Charmerace ...

everything that Guerchard must have to induce M.Formery to proceed.

But still, there is a risk--I think I'd better have those things handy in case I have to bolt." He went into his bedroom and came back with the key of the safe and a kit-bag.