"You are going to see Mrs Gabriel?" said the detective. "Yes. Where have you been, Marton?" "I have been trying to see her, but she is ill--at least so the butler says. I suspect, however, this is a lie. She doesn't want to see me!" "Shall I--" "Yes, you go up. I must return to the hotel and get some dinner. I have been walking and thinking until I am worn out. I'll wait your return, and we can talk over the matter." "What matter?" "The conspiracy of Mrs Gabriel and Hale," said Marton, promptly. "Get on with you, Haverleigh. I'm off to dinner." And he went away at a quick pace, leaving Leo much astonished. However, there was no use in standing and wondering, so he pursued his way. As Mrs Gabriel was said to be ill, and had denied herself to Marton, it was not unlikely that he would be treated in the same way. Therefore, instead of going to the front door, Leo went round the castle on to the terrace. This was shut off from the rest of the ground by a high fence with a gate in it. Leo had retained the key of this gate and had no difficulty in getting in. The room which looked on to the terrace was lighted, but the blinds were down. Leo peered in. He saw Mrs Gabriel seated in a chair. Standing near her was Mr Richard Pratt. CHAPTER XV A NEW COMPLICATION Leo was so surprised by this unexpected sight that for the moment he stood still. Then he made up his mind to interview the pair. Mrs Gabriel and Pratt evidently understood one another, and the two of them together might probably tell him more about himself than one would do. Moreover, Leo was angry at the way in which Pratt had let him lie under the imputation of being a thief when he could have lifted the disgrace from off his shoulders. Certainly Pratt could have done so only at the risk of incriminating himself, but at the time Leo was too much annoyed to think of this. He saw that there was some mystery, and thinking it might have to do with Mrs Gabriel's enmity towards himself, he interrupted what seemed to be a furious conversation by knocking at the window. Mrs Gabriel and Pratt turned in the direction where the sound came, she with a pale face, and Pratt with a levelled revolver which he took from his breast pocket. Leo might have been in danger of his life, but that he chanced to remember a peculiar tune which Pratt had taught him, in order to announce his coming while he was staying at The Nun's House. At the time Leo had thought this was only a freak of the old man's, but now that he knew who Pratt was, he saw that there was use in it, to Pratt if not to himself. At all events, he began to whistle. Hardly had he got through the first few bars before Pratt's watchful attitude relaxed, and he tossed the revolver on to the table. Mrs Gabriel still continued to look agitated, but Pratt stepped towards the window and opened it coolly.