"My dear Cleek," he said, "as you appear to know all about Sir Henry and his famous mare, there's no need to go into that part of the subject, so I may as well begin by telling you at once that Sir Henry has come up to town for the express purpose of getting you to go down to his place in Suffolk to-night in company with him, as his only hope of outwitting a diabolical agency which has set out to get at the horse and put it out of commission before Derby Day, and in the most mysterious, the most inscrutable manner ever heard of, my dear chap. Already one groom who sat up to watch with her has been killed, another hopelessly paralysed, and to-night Logan, the mare's trainer, is to sit up with her in the effort to baulk the almost superhuman rascal who is at the bottom of it all. Conceive if you can, my dear fellow, a power so crafty, so diabolical, that it gets into a locked and guarded stable, gets in, my dear Cleek, despite four men constantly pacing back and forth before each and every window and door that leads into the place and with a groom on guard inside, and then gets out again in the same mysterious manner without having been seen or heard by a living soul. In addition to all the windows being small and covered with a grille of iron, a fact which would make it impossible for anyone to get in or out once the doors were closed and guarded, Sir Henry himself will tell you that the stable has been ransacked from top to bottom, every hole and every corner probed into, and not a living creature of any sort discovered. Yet only last night the groom, Tolliver, was set upon inside the place and killed outright in his efforts to protect the horse; killed, Cleek, with four men patrolling outside, and willing to swear--each and every one of them--that nothing and no one, either man, woman, child or beast, passed them going in or getting out from sunset until dawn." "Hum-m-m!" said Cleek, sucking in his lower lip. "Mysterious, to say the least. Was there no struggle? Did the men on guard hear no cry?" "In the case of the first groom, Murple, the one that was paralysed--no," said Sir Henry, as the question was addressed to him. "But in the case of Tolliver--yes. The men heard him cry out, heard him call out 'Help!' but by the time they could get the doors open it was all over. He was lying doubled up before the entrance to Black Riot's stall, with his face to the floor, as dead as Julius Caesar, poor fellow, and not a sign of anybody anywhere." "And the horse? Did anybody get at that?"