"Yes, he lives here," said Beale, "but I am afraid he is not at home."
He thought it might be a patient or a summons to a patient.
"Not at home?" The man's face fell. "But how unfortunate! Could you tell me where I can find him, my business is immediate and I have come a long way."
From Germany, guessed Beale. The mail train was due at Charing Cross half an hour before.
"I am a friend of Doctor van Heerden and possibly I can assist you. Is the business very important? Does it concern," he hesitated, "the Green Rust?"
He spoke the last sentence in German and the man started and looked at him with mingled suspicion and uncertainty.
"It is a matter of the greatest importance," he repeated, "it is of vital importance."
He spoke in German.
"About the Green Rust?" asked Beale, in the same language.
"I do not know anything of the Green Rust," said the man hurriedly. "I am merely the bearer of a communication which is of the greatest importance." He repeated the words—"the greatest importance."