Translations for double-edged in French

Here are paragraphs from public domain books translated:

"You see," remarked Holmes, as we paced to and fro in front of the house, "this marriage rather simplifies matters. The photograph becomes a double-edged weapon now. The chances are that she would be as averse to its being seen by Mr. Godfrey Norton, as our client is to its coming to the eyes of his princess. Now the question is, Where are we to find the photograph?"	— Vous comprenez, dit Holmes, que ce mariage simplifie singulièrement les choses. La photographie est maintenant une arme à double tranchant. Il est probable que la dame redoute autant de la laisser voir à M. Godfrey Norton que notre client à la princesse. Maintenant la question est celle-ci : où trouverons-nous cette photographie ?
The Adventures of Sherlock Holmes, by Arthur Conan Doyle	Les Aventures de Sherlock Holmes, de Arthur Conan Doyle