Morrison, Arthur: The Red Triangle. V1. 4 Sep 2009
 

Arthur George Morrison (November 1, 1863 London - December 4, 1945) was an English author and journalist, known for his realistic novels about London's East End and for his detective stories.

Excerpt
I have already recorded many of the adventures of my friend Martin Hewitt, but among them there have been more of a certain few which were discovered to be related together in a very extraordinary manner; and it is to these that I am now at liberty to address myself. There may have been others—cases which gave no indication of their connection with these; some of them indeed I may have told without a suspicion of their connection with the Red Triangle; but the first in which that singular accompaniment became apparent was the matter of Samuel’s diamonds. The case exhibited many interesting features, and I was very anxious to report it, with perhaps even less delay than I had thought judicious in other cases; but Hewitt restrained me.