The stoop-shouldered crook pursued his path along a turning corridor. He was in a veritable catacomb. Now two other passages joined this one. All terminated before an iron-sheeted door.

This was the final barrier. Spotter had reached the heart of Loo Look’s domain. He was at the entrance to the opium den.

The door opened as though invisible eyes had witnessed the little man’s approach. Spotter stepped into a long, low room. It was a squalid place; but its filthiness was somewhat less noticeable because of the dim lights.

A slender, wiry Chinaman stood by the door. He was Loo Look’s most trusted watchman, the keeper of the inner den. He motioned Spotter forward.

The walls of the room were lined with dirty curtains. These hid the bunks in which the slaves of the poppy reclined, smoking their pipes.

The room was like a corridor, with berths on either side. No attempt had been made to make the place attractive. That was unnecessary.

Those who came there cared nothing for the appearance of the den. Why should they? When the pipes began to smoke, dreaming minds would supply the grandeur that was lacking. Spotter knew all this.

The guardian of the den steered Spotter to a bunk. The curtains closed on the little gangster. He was provided with a pipe, and he lay silently waiting.

Spotter was not addicted to the use of opium. Yet to-night he decided to try a few puffs — something which he had done before.

Vague minutes went by. The little, stoop-shouldered man peered from between the curtains. The room seemed strangely silent. Spotter avoided further puffs on the pipe. He was wise enough to avoid too much of the influence of the overpowering drug.