The Lair of Sosthenes Silly (Le Repaire de Sosthène Silly in the original French) is a comic story possibly written by Blanche Dumoulin, Rob-Vel and/or Luc Lafnet, and drawn alternatingly by Luc Lafnet, Rob-Vel and Blanche Dumoulin (confusingly signing with Lafnet's pen name “Davine”),. It features Spirou, Bill Money, Mr Papyrus, and, in their debuts, Spip the Squirrel, Sosthenes Silly, the Messenger Robot, Biscornu, Green Lotus, the Robot of Death, Tom Winkle, Silly's Sea Monster, . Mussol, Julius Caesar, Thutmes and the god Ra are mentioned.
Adrift at sea following the end of their last adventure, Spirou, Bill Money, Mr Papyrus wash up on a mysterious Ancient Egypt-themed underwater base, ruled by a mad scientist-turned-pharaoh, the malevolent Sosthenes Silly. In a world of robot servants and hypnotic control, the three travellers must brave Doctor Silly's mad designs to rescue Biscornu, Green Lotus and Spip, the three living prisoners of Pharaoh Sosthenes' death-trap!
- The explorer Mussol died in 1889.
- Sosthenes Silly calls his island “the Kingdom of the Wise”.
- Mr Papyrus recognises the hieroglyphs used by Silly as dating back to “the Ramses II Dynasty”. One of the rooms in the Kingdom of the Wise is named for Ramses, and others for “the God Rah” and Thutmes.
- Sosthenes Silly was once an illustrious egyptologist, scientist, inventor and automaton-constructor. He disappeared from “the continent” in 1910 alongside his friend Tom Winkle, building the Kingdom of the Wise to develop robots who would help Mankind.
- Sosthenes uses the hypnotic “Pharaonic Superwaves” to force people to go along with his Ancient Egyptian delusions.
- Green Lotus is Sosthenes' niece, whom he hypnotised with the Pharaonic Waves into playing the part of an Egyptian Queen.
- The Army of Automata kept in the Thutmes Room obey whoever speaks the formula “”.
- Spirou swears by “all the Pharaohs in the Old Testament”.
- Because the Sea Monster is technically a reptile, Spirou is able to charm him using snake-charming techniques.
- Spirou can play the harmonica.
- Sosthenes Silly's ultimate experiment is a huge robot which will require a live human being as its “heart”. He initially wants to use Tom Winkle as the heart of the robot, but, in his rage, eventually seals himself into the chamber instead.
- The second serialized Spirou adventure, The Lair of Sosthenes Silly begins immediately after the end of The Inheritance of Bill Money (1938) and leads directly into The Billionaire's Son (1940). Indeed, Sosthenes Silly is sometimes lumped together with Inheritance as a single story, with even The Billionaire's Son sometimes being added to the mix.
This story was serialized from Le Journal de Spirou #12-39 to #1-40, over 21 weeks. It was reprinted in the Spirou par Rob-Vel collection of all of Rob-Vel's Spirou comics. It has not known an official English printing to this day.
Like Spirou's earlier one-pagers, The Inheritance of Bill Money was signed Rob-Vel but in truth mostly drawn by Luc Lafnet and Blanche Dumoulin. It is not known precisely who wrote the story, though the artist's wife Dumoulin is a commonly-cited candidate, who may also have taken care of the lettering.
As detailed above, it is common to lump together The Inheritance of Bill Money and its sequel The Lair of Sosthenes Silly as a single story; though there are good arguments on both sides, and as always with long serials it is ultimately arbitrary to establish exact cuts, this Wiki chooses the option to instead consider them separate stories, largely due to the two different main antagonists and to the different authorships.