The Silent House by Fergus Hume

Unwilling to give up prosecuting the Vrain case while the slightest hope remained of solving its mystery, Lucian sought out Link, the detective, and detailed all the evidence he had collected since the constituted authorities had abandoned the matter. Although Mrs. Vrain and Ferruci had exculpated themselves entirely, Denzil thought that Link, with his professional distrust and trained sense of ferreting out secrets, might discern better than himself whether such exculpations were warranted by circumstances.

Link heard all that Denzil had to tell him with outward indifference and inward surprise; for while unwilling, through jealousy of an amateur, to flatter the barrister by a visible compliment, yet he silently admitted that Denzil had made his discoveries and profited by them with much acuteness. What annoyed him, however, was that the young man had pushed his inquiries to the uttermost limit; and that there was no chance of any glory accruing to himself by prosecuting them further. Still, on the possibility that something might come of it, he went over the ground already traversed by the amateur detective.