Art Painting

'I felt his breath on my face!' cried Daddy Jacques.
"'Where is he?' - where is he?' we all cried.
"We raced like madmen along the two galleries; we visited doors and windows - they were closed, hermetically closed. They had not been opened. Besides, the opening of a door or window by this man whom we were hunting, without our having perceived it, would have been more inexplicable than his disappearance.
"Where is he? - where is he? - He could not have got away by a door or a window, nor by any other way. He could not have passed through our bodies!
"I confess that, for the moment, I felt 'done for.' For the gallery was perfectly lighted, and there was neither trap, nor secret door in the walls, nor any sort of hiding-place. We moved the chairs and lifted the pictures. Nothing! - nothing! We would have looked into a flower-pot, if there had been one to look into!"
When this mystery, thanks to Rouletabille, was naturally explained, by the help alone of his masterful mind, we were able to realise that the murderer had got away neither by a door, a window, nor the stairs ?a fact which the judges would not admit.