Third part of the Secret De L'Espadon storyline which was initially published periodically in Le Journal De Tintin from September 26 1946 onwards. In albums, this didn't exist when the story was separated in two parts by Le Lombard in the fifties, its content being included in the previous album. When Les Editions Blake Et Mortimer took over the rights, they republished the story in three parts, this one coming out in 1986. In 2002 it was reintegrated to the two previous issues as a single all-encompassing edition.
Collected in Le Secret de l'Espadon - Intégrale.