The expression on Mr. Cass's face was one half of relief, half of uneasiness.
"What do you mean, then?" he demanded. "I have a right to know."
"You shall know. It was in order to tell you that I came over this evening. But first, have you the remaining links?"
Mr. Cass crossed the room to an old-fashioned desk which stood in a corner, and began to search. In five minutes he returned to his seat by the fire, bringing with him an oval enamelled with a pack of cards.
"That is all I have," he said. "Mildred has the one with the horse on it; you have the other with the champagne bottle."
"And the ballet girl? Where is that one?" Mr. Cass was silent and shifted uneasily in his chair. "That I cannot tell you until I know more clearly what you have discovered."
"You shall know all. It may save a certain person from a relentless enemy. Yes; you may look, Mr. Cass! I tell you there is one man who hates another with all the intensity of his soul, and will only too willingly do him an injury."
Mr. Cass began to grow angry at this mysterious description. "One man--another man?" he repeated. "What do you mean? Who is the enemy?"
"Julian Roper."
"And who is he?" Heron looked at him in astonishment. If faces were to be read, his host knew nothing of this man. "I am surprised that you do not know who Roper is," he said, slowly.