Gently questioned by me, Darzac denied having, on that evening, or on any other, purchased a cane at Cassette's.

However," said Rouletabille, "I'll not swear to anything; Monsieur Darzac has such strange fits of silence that one does not know exactly what to think of what he says." "To Frederic Larsan this cane must mean a piece of very damaging evidence.

But in what way?
The time when it was bought shows it could not have been in the murderer's possession." "The time doesn't worry Larsan.

He is not obliged to adopt my theory which assumes that the murderer got into The Yellow Room between five and six o'clock.

But there's nothing to prevent him assuming that the murderer got in between ten and eleven o'clock at night.