Holmer, his voice quiet but with a sudden edge to it, said, "There's a car following us. I wasn't sure till we got through the Tunnel." With sudden reaction, Birrel's hopes leaped. Then Connor and the others had come to in time to follow? Yet it hardly seemed possible.... "Vannevan!" Kara's exclamation was so fierce that it startled him. "It can't be anybody else," Holmer grimly agreed. "That newspaper story about the captured spy—it drew him to the prison too, it seems." Whoever Vannevan might be, Birrel thought, it was evident that these two hated and feared him like the devil. Holmer gripped the wheel tighter, and the car suddenly lunged faster. He said, without turning, "You know what it means. The Irrians know now that we followed them to Earth. Hold on, we have to lose them!" As by a lightning-flash, the shocking truth was abruptly revealed to Birrel. Two groups of secret agents, bitterly hostile to each other, playing a vast and deadly game against each other, were on the unsuspecting Earth! CHAPTER IV Birrel felt the imminence of onrushing danger. Danger, not just to himself, but to all his world. For in him lay the only chance to find out about the threat to Earth before it materialized. Who their pursuers were, who the Irrians and Vannevan might be, and why they had come to Earth, he could not guess. But about Kara and Holmer, he was sure. Their colleague, the dead Rett, had had those pictures of Earth's most secret weapons and defenses on him. They, therefore, were the danger—and he must not lose them. "Turn at the next side road!" he said to Holmer. "We can give them the slip in the back roads." Holmer nodded. Birrel looked back. A pair of headlights swung steadily along a quarter-mile behind them. "They're closer," said Kara. Birrel looked ahead, saw the sign that marked a crossroad, and said, "Turn there!" Next moment, he thought they were all three done for. For Holmer turned into the dark side road without slowing down at all, and the sedan careened on screaming tires and threatened to go over.