The Gay Triangle by William Le Queux

The heat was stifling in the Gran Ancora at Barcelona, an obscure but grandiloquently named cafe of more than doubtful reputation. At dilapidated tables in the long apartment which served as a saloon groups of rough-looking men were drinking steadily. The fumes of strong tobacco poisoned the heavy atmosphere, flies swarmed over everything, the air was full of the reek of stale drink and unwashed humanity.

Though it was but early evening the ill-omened place was already filling up. It was a notorious haunt of betting men and some of the worst characters of the town, frequented by desperadoes who were ready to undertake any deed of violence if it offered the promise of plunder. The swarms of anarchists, who are the curse of Spain, found there a ready welcome and congenial companionship.