"Of course, sir, I quite understand this is not the sort of thing or the sort of place to which you are accustomed," he said, waving a deprecatory hand round the shabby little parlour. "But in this particular case, I and my friend--that friend I may say at the moment is elsewhere taking his observations--wanted to lie low. It didn't enter into our scheme to put up at a swagger hotel, and run the risk of gossip. It might have reached the ears of those we are after, and scared them off." Hugh listened attentively. There was something very serious in the wind now, and the dwellers at Rosemount were as yet unaware of what was impending. His surprise expressed itself in the direct question which he shot at the detective: "I take it you are here to arrest them, then?" "One of them, the man," corrected Mr Davidson, quietly; "we know a good deal about the girl, but we have no evidence that implicates her beyond the fact of her association with him, and from our point of view that means nothing in a Court of Law." "What is his offence?" asked the startled Hugh. "Forgery," was the laconic answer. "He belongs to a pretty well-known gang, and we have had our suspicions of him for a long time now, but he was devilish clever and cunning. Several of his pals were caught, but it was always difficult to rope him in. We shouldn't have got him now but for the fact of one of his pals peaching. And even now, although the evidence is strong enough for us, I doubt if it is strong enough to get him more than a comparatively light sentence. If he can lay hold of a clever counsel, and there will be some money at the back of him, if not a great deal, he won't come off so badly." So Mr Burton was a criminal, and had been living in Blankfield on the proceeds of his nefarious calling. The rich uncle in Australia who had left him a comfortable fortune was a myth. "I suppose he has been on the `crook' all his life?" queried Hugh. "Ever since he has come under our observation," was the reply of the detective. "Before he joined the present gang, a few of whom we have collared from time to time, card-sharping was his lay. Once he rented an expensive flat in Paris, and I believe made a tidy bit out of it. That is where the young lady first appeared upon the scene." "But how long ago is that? She doesn't look more than twenty." "I know," said Mr Davidson. "She looks wonderfully young, that is one of her assets. As a matter of fact I should say she was twenty-four at the least. The Parisian episode occurred about five years ago, making her nineteen at the time. He was there about twelve months, at the end of which time he got an introduction to the forging gang, and chucked the cards in favour of a more remunerative game." "She acted, I suppose, as a decoy and confederate?" "So I am given to understand. She very seldom played herself, but used to signal the opponents' cards to him."