In a first-floor oak-panelled suite at the Albany, overlooking the covered walk that runs from Piccadilly to Burlington Gardens, they found an excessively fair, loose-limbed man whose air of rather helpless timidity was heightened by a pair of large tortoise-shell spectacles. He appeared excessively embarrassed at the sight of MacTavish’s extremely good-looking companion. “You never told me you were bringing a lady, Euan,” he said reproachfully, “or I should have attempted to have made myself more presentable.” He looked down at his old flannel suit and made an apologetic gesture which took in the table littered with books and papers and the sofa on which lay a number of heavy tomes with marked slips sticking out between the pages. “I am working at a code,” he explained. “Ernest here,” said MacTavish, turning to Mary, “is the code king. Your pals in the Intelligence tell me, Ernest, that you’ve never been beaten by a code ...” The fair man laughed nervously. “They’ve been pullin’ your leg, Euan,” he said. “Don’t you believe him, Mary,” retorted her cousin. “This is the man who probably did more than any one man to beat the Boche. Whenever the brother Hun changed his code, Brother Ernest was called in and he produced a key in one, two, three!...” “What rot you talk, Euan!” said Dulkinghorn. “Working out a code is a combination of mathematics, perseverance, and inspiration with a good slice of luck thrown in! But isn’t Miss Trevert going to sit down?” He cleared the sofa with a sweep of his arm which sent the books flying on to the floor. “Ernest,” said MacTavish, “I want you to give Miss Trevert here a letter to some reliable fellow in Rotterdam who can assist her in making a few enquiries of a very delicate nature!” “What sort of enquiries?” asked Dulkinghorn bluntly. “About a firm called Elias van der Spyck,” replied Euan. “Of Rotterdam?” enquired the other sharply. “That’s right! Do you know them?” “I’ve heard the name. They do a big business. But hadn’t Miss Trevert better tell her story herself?” Mary told him of the death of Hartley Parrish and of the letter she had found upon his desk. She said nothing of the part played by Robin Greve. “Hmph!” said Dulkinghorn. “You think it might be blackmail, eh? Well, well, it might be. Have you got this letter about you? Hand it over and let’s have a look at it.” His nervous manner had vanished. His face seemed to take on a much keener expression. He took the letter from Mary and read it through. Then he crossed the room to a wall cupboard which he unlocked with a key on a chain, produced a small tray on which stood a number of small bottles, some paint-brushes and pens, and several little open dishes such as are used for developing photographs. He bore the tray to the table, cleared a space on a corner by knocking a pile of books and papers on the floor, and set it down. “Just poke the fire!” he said to Euan.