Lord Galton went smartly up to the bunch of coats, plunged his hand into the left-hand pocket of that one wretched old garment, and turned it sharply inside out, so that the damning evidence should fall before his cousin's eyes. There fell out no small amount of gathered dirt, some paper torn into minute fragments, and a stub of pencil; also a rather repulsive handkerchief--nothing more. Nothing rang upon the hall floor. There was no Emerald. Lord Galton for once did a weak thing--or a superstitious one. As though not trusting his senses, he picked the repulsive handkerchief up and shook it. But there was no emerald. Indeed, one could see and hear by the way it had fallen that there was no emerald within its large but unattractive folds. He knew that well enough before he touched the rag--but it was a forlorn hope. It was the older man who hastily picked up these evidences, not of the Professor's dishonour, but his own, and rapidly put them back where they belonged; darting a glance over his left shoulder and sighing with relief to find that there was still no one about, not the sound of a distant footfall, not the glide of a serf. His companion's face was darker and flushed. "I could have sworn ..." he opened. Then he added, murmuring, "He must have taken it away." "I wish we hadn't ..." began the Home Secretary, and then switched off to, "You're quite sure you saw it with your own eyes, Tommy?" "Absolutely certain," said the young man, with a fearless steady gaze, and proud to be telling one truth at least. The Home Secretary held his chin in his hand, stood silent for a good quarter of a minute, and then said something characteristic of his profession as a statesman. He said, "Humm!" * * * * * * * What had happened? Dear--or, if that is too familiar a term--charming reader, this is not one of the detective stories of commerce. You shall know all about it beforehand, as you have already known all about it, step by step. You shall be subjected to no torture of suspense. We will leave that to the people of our story. They were born for it. What had happened was simple enough. The Professor had gone off to the library. He wanted to make certain of the Society at Berne in the _Almanac de Gotha_. With men such as he, an obsession having cropped up has a horrid fascination for the mind and holds it. He was worrying about the exact title: whether it was Crystallographique, or Crystallographische, or de Crystallographic. He was determined to get it right.