For another ten minutes neither man said a word. A big drop of moisture collected on the cleft in the middle of Ostby's chin. He wished he were certain that he could trust Groves. Groves was an open-faced young man with candor in his blue eyes, and a ready smile that asked for confidence, but somewhere in the man's makeup was a black streak, Ostby reckoned. All morning Ostby's infallible intuition had throbbed a slow pulse of warning. He knew better than to disregard that warning but when he turned to thieves for help he had no right to expect sterling characters for companions. Siggen should have enough control over his men to make Groves afraid to double-cross him. And, strangely enough, Ostby trusted Siggen. His intuition told him that Siggen was a man true to his own principles, distorted though they might be. Ostby had seen another facet of Siggen's character that morning. When he had returned to the house Siggen had introduced him to Groves, and the three of them had gone down into the fat man's basement. "I want to show you a pretty sight," Siggen said. Lying on the basement floor was the body of a man. A knife was buried in his throat. The dead mouth that smiled up at Ostby was widened by a long scar. "What will we do when we get in the Stalls?" Groves interrupted Ostby's reflections. Ostby did not answer, but turned his head to look at the young man, long and levelly. "It's none of my business, of course," Groves added hurriedly, "but I won't be much help in case of trouble if I don't even know what you're trying to do." "If trouble comes we just get out as fast as we can." "You aren't going to try to get one of the slaves out, are you? You told Siggen that you only wanted to get in, and get out again." "That's all I want." "It you're trying to close the 'door,' what would you want in...." Abruptly Groves stopped talking. Ostby read the dismay in his voice as he realized that he had said too much. Ostby rolled over on his side, bringing his gun up and firing in the same motion. Groves had his own gun drawn when the slug caught him in the forehead and slapped his head back as though riding the blow of a fist. Slowly he fell sideways along the wall. Ostby was on his feet immediately. He'd have to move fast now, he knew. No one but the police, or someone high in the Imperator's confidence, would know that he was here to close the "door" between the worlds. Groves had made a bad slip. In Groves' right rear pocket Ostby found a black billfold. Inside was a white card with the word, _Confidential_, written on it. He found nothing else of interest. But that was enough to wipe away Ostby's last doubt. Sweat broke out anew on his forehead as he realized how close the trap had come to closing around him. He might be too late already.