"A door into the infinite outside," repeated Ennis broodingly, looking past the inspector. Then he made a sudden movement of wild impatience, the dread leaping back strong in his eyes again. "Oh, what good is all this talk about Doors and infinite universes doing in finding Ruth? I want to _do_ something! If you think this mysterious Brotherhood has taken her, you must surely have some idea of how we can get her back from them? You must know something more about them than you've told." "I don't know anything more certainly, but I've certain suspicions that amount to convictions," Inspector Campbell said. "I've been working on this Brotherhood for many years, and block after block I've narrowed down to the place I think the order's local center, the London headquarters of the Brotherhood of the Door." "Where is the place?" asked Ennis tensely. "It is the waterfront café of one Chandra Dass, a Hindoo, down by East India Docks," said the detective officer. "I've been there in disguise more than once, watching the place. This Chandra Dass I've found to be immensely feared by everyone in the quarter, which strengthens my belief that he's one of the high officers of the Brotherhood. He's too exceptional a man to be really running such a place." "Then if the Brotherhood took Ruth, she may be at that place now!" cried the young American, electrified. Campbell nodded his bald head. "She may very likely be. Tonight I'm going there again in disguise, and have men ready to raid the place. If Chandra Dass has your wife there, we'll get her before he can get her away. Whatever way it turns out, we'll let you know at once." "Like hell you will!" exploded the pale young Ennis. "Do you think I'm going to twiddle my thumbs while you're down there? I'm going with you. And if you refuse to let me, by heaven I'll go there myself!" Inspector Pierce Campbell gave the haggard, fiercely determined face of the young man a long look, and then his own colorless countenance seemed to soften a little. "All right," he said quietly. "I can disguise you so you'll not be recognized. But you'll have to follow my orders exactly, or death will result for both of us." That strange, hooded dread flickered again in his eyes, as though he saw through shrouding mists the outline of dim horror. "It may be," he added slowly, "that something worse even than death awaits those who try to oppose the Brotherhood of the Door--something that would explain the unearthly, superhuman dread that enwraps the secret mysteries of the order. We're taking more than our lives in our hands, I think, in trying to unveil those mysteries, to regain your wife. But we've got to act quickly, at all costs. We've got to find her before the great gathering of the Brotherhood takes place, or we'll never find her." * * * * *