* * * * * In some hidden spot outside the temple something went _plunk_. The sound was not sharp enough to be called an explosion. It was a plunk, like a rock falling in a rain barrel. A small round object arched slowly through the air and hit on the roof of the temple. It also went _plunk_. No explosion. Just a _plunk_. A cloud of white smoke puffed out. "What the devil is that?" Craig thought uncertainly. "Are they throwing grenades at us? Was the first grenade a dud?" He started toward the grenade. A whiff of the smoke stung his nostrils, sent a warning bell clattering wildly in his brain. "Gas!" he yelled. "They're throwing gas grenades at us. Stay away from that smoke." The Ogrum had attacked the Idaho with their sleeping gas! The guards in the temple had carried sacks of what Craig had thought were ordinary grenades. They had been gas grenades! _Plunk_ went the projector outside the temple. _Plunk_ went the grenade that struck on the roof. _Plunk, plunk, plunk_--A shower of grenades came over. Gas swirled over the roof of the temple. "Knock out those projectors!" Craig shouted. He leaped to the wall of the temple, began firing. All around him other guns were letting go. Up to now it had been necessary to conserve ammunition as much as possible. If the projectors were not knocked out, no amount of ammunition would do the humans any good. The rattle of sub-machine guns was a continuous tumult of sound. Fires still burned in the city and the air was becoming heavy with smoke. All around the temple the Ogrum were lurking. They were not venturing into the open. Now and then they could be glimpsed darting from shelter to shelter. _Plunk--plunk--plunk--_ More gas grenades hit on the roof. Somewhere near him Craig heard a man choke and gasp for breath. Everywhere, even above the rattle of the machine guns, he could hear men coughing. Something stung his lungs and he coughed himself. The machine gun fire began to thin out as choking men dropped their guns. Craig found himself firing blindly, searching for the hidden projectors. The plunk of the gas grenades was loud in his ears. "Tough luck," a thin voice said near him. He looked around and saw Margy Sharp. The girl was holding a handkerchief over her nose and was trying to keep from breathing. She was swaying. "I feel like I want to go to sleep," she whispered. The gas was getting to her. It was getting to others, too. Many of the sailors had fallen. Some of them were trying to drag themselves back to the edge of the roof, trying to lift guns with hands that no longer had the strength for the task. "We fought a good fight," Margy Sharp whispered. "Too bad we lost." "We haven't lost yet," Craig gritted. He was lying and he knew it. His only hope was phase four of the attack plan. Unless phase four went into operation within the space of minutes, they were doomed. "What the hell has happened to Michaelson?" he thought.