On the way to the spot Jennings conversed with Twining in low tones and detailed his experience with Maraquito. "I am quite sure that she has gone to the factory," he said; "she does not think that I know about it. I fancy she will tell her pals that the game is up and the lot will light out for America." "They may have gone by this time," suggested the inspector. "I don't think so. Maraquito must have just arrived, if indeed she has come here. Besides, she will never guess that I know how to get into the place, or indeed think that I know of its existence." "How did you guess?" "Guess is a good word. I just did guess, Twining. From various facts which there is no time to tell you, I became convinced that there was a factory in existence. Also I fancied that the death of that old lady was connected with the preservation of the secret. But I only got at the hard facts the other day, when a girl called Grant--" "I remember. She gave evidence at the inquest." "Precisely. Well, she brought me some plans belonging to her father which she found. He was engaged in a quiet job hereabouts five years ago, and died when it was finished. He was poisoned with arsenic." "What! like that man Tyke?" "Yes. The person who runs this show--Maraquito, I think--evidently has a partiality for that extremely painful poison. Well, this workman having constructed the secret entrance, was got out of the way by death, so that the secret might be preserved. And I guess Miss Loach was settled also in case she might give the alarm." "But if the secret entrance is in the cottage," said Twining, "this old woman may have been aware of its existence." "Certainly, and was about to split when she was killed. At least, that is my theory." "She must have been in with the gang." "I have never been able to fix that," said Jennings thoughtfully. "I know she was a lady and of good birth. Also she had money, although she condemned herself to this existence as a hermit. Why she should let Maraquito and her lot construct a secret entrance I can't understand. However, we'll know the truth to-night. But you can now guess, Twining, how the bell came to be sounded." "No, I can't," said the inspector, promptly. "I forgot. You don't know that the secret entrance is in the room where Miss Loach was murdered. Well, one of the gang, after the death, sounded the bell to call attention to the corpse, and then slipped away before Susan Grant could get to the room." "But why should this person have sounded the bell?" "That is what I have to find out. There's a lot to learn here." "Have you any idea who killed Miss Loach?" "Maraquito, under the disguise of Mrs. Herne." "Was she Mrs. Herne?" "Yes. She masqueraded as an invalid who could not leave her couch, but I managed to get at the truth to-night." "But from the evidence at the inquest, Mrs. Herne was out of the house when the blow was struck."