"In Zambesi. There are plenty of them there in the rivers and mango swamps. Some hunters stake a dog overnight by the river bank, and the animal gives them warning of the approach of the reptiles by howling with terror. It is rather cruel--to the dog." "Undoubtedly," said Caldew. "How are you getting on with your investigations in this case?" continued Musard, abruptly changing the conversation. Caldew was instantly wary, and stiffened into an attitude of official reserve, wondering why Musard should seek to question him about the murder. "I am an old friend of the Herediths," continued Musard, as though divining the other's thoughts. "This murder is a very terrible thing for them. I am afraid it may mean Sir Philip's death-blow. He is old and feeble, and the shock, and his son's illness, have had a very bad effect on him. I should have gone to France to-day for the War Office, but I arranged for somebody to go in my place in order to remain with the family in their hour of trial. Have you found out anything which leads you to suppose you are on the track of the murdered?" "I am afraid I cannot tell you anything about the investigations," replied the detective cautiously. "I am not in charge of the case, you know." "I understand," rejoined the other, with a nod. "Perhaps I should not have asked you. My anxiety must be my excuse." He uttered this apology so courteously and pleasantly that Caldew felt momentarily ashamed of his own rigidly official attitude. But his instincts of caution quickly reasserted themselves, and he told himself that in this sinister case it was his business to be on his guard and talk to nobody. The situation was terminated by the reappearance of Miss Heredith from a door at the side of the house. The detective was a little surprised to see her again, for he had conceived the idea that she had gone indoors to avoid meeting him. She went eagerly to Musard without noticing him. "Oh, Vincent!" she exclaimed, and the look of relief on her face was unmistakable. "Sir Ralph Horton is just leaving. He says that Phil has passed the crisis, and there is no need for him to stay any longer. Phil still needs great care and attention, but Sir Ralph says it will be quite safe to leave him in Dr. Holmes's hands. There is no fear for his brain, thank God." "This is good news," said Musard. "Have you told Sir Philip?" "Not yet. I thought it better to defer it until after dinner. I want you to tell him then." Miss Heredith turned as though to re-enter the house, but Caldew, who had been hovering a few paces away within earshot of this dialogue, approached her with the gold chain in his hand.