The Dangerfield Talisman by J.J. Connington

Conway Westenhanger had never pretended, even to himself, that he had a natural gift for detective work. He had quite frankly recognised that only good luck could bring him to success in his search for the taker of the Talisman; and a retrospect over the events of the week served merely to confirm the idea. None the less, the history of the case caused him to feel a touch of chagrin. While he had been following out erroneous inductions, the two Dangerfields had gone straight to the mark; and if he had actually beaten them by a short head in the end, it was by good luck and nothing else. In fact, he had profited by their manœuvres in the matter of the Talisman's return. Without that incident, he would have been unable to discover anything at all.

Now, so far as he was concerned, the episode seemed to have reached its end, but when he thought over the whole affair, one point still remained a mystery to him. Why had old Rollo shown that touch of dismay at a reference to the Dangerfield Secret? The thing had been only momentary, but it had been unmistakable, and Westenhanger had seen it twice over within a very short period. The first time, he recalled, was when he had hinted to Rollo that he had stumbled on the Secret; the second occasion was when he had shown signs of asking questions which, possibly, might touch the same subject.