You always take things in such an impossible way ...

Come along! Come!" And she literally dragged him away, for he was obstinate and wanted to remain by the trap-door; that hole attracted him.
Suddenly, the trap-door was closed and so quickly that they did not even see the hand that worked it; and they remained quite dazed.
"Perhaps HE was there," Raoul said, at last.
She shrugged her shoulders, but did not seem easy.
"No, no, it was the 'trap-door-shutters.' They must do something, you know ...

They open and shut the trap-doors without any particular reason ...

It's like the 'door-shutters:' they must spend their time somehow." "But suppose it were HE, Christine ?" "No, no! He has shut himself up, he is working." "Oh, really! He's working, is he ?" "Yes, he can't open and shut the trap-doors and work at the same time." She shivered.
"What is he working at ?" "Oh, something terrible! ...

But it's all the better for us...