The airlock was only a dozen blocks away. The Chief's theory had been that the government, depending on surprise in its move to surround the Childress Barber College, would not attempt the complicated task of checking all traffic passing through the airlock until it was realized that some of the Phoenix men had escaped from the trap at the college. Dark reached the airlock in minutes. The Chief's theory proved correct. There were no police at the airlock, and the maintenance employee stationed there did not even look up as Dark's approach activated the inner door. He drove the groundcar into the airlock. The inner door closed behind him. The outer door opened, and Dark drove out onto the highway that struck straight across the Syrtis Major Lowland toward the Aeria Desert and Edom. It was as simple as that. About ten miles out was the circular bypass highway that surrounded Mars City, and Dark proposed to turn right on that, for his destination was Hesperidum. The highway he was on would take him eastward, and Hesperidum was about 8,000 kilometers southwest of Mars City--a little better than two-days' drive at groundcar speed on the straight, flat highways. Dark reached over and set the groundcar's radio dial on the frequency which had been agreed on for emergency Phoenix broadcasts during this operation. If government monitors caught the broadcasts and jammed them, there were alternate channels chosen. With only about two dozen radio stations on all Mars, plus the official aircraft and groundcar band, there was plenty of free room in the air. There was nothing on the Phoenix frequency now but a little disconsolate static. The country through which he drove here was uninhabited lowland. The human life on Mars, agricultural, industrial and commercial, was concentrated under the domes of the cities. Except for a few tiny individual domes at the edge of Mars City, there were no human structures close to it except the airport and the spaceport, and these were west and north of the city, respectively. The highway struck straight and lonely through a faintly rippling sea of gray-green canal sage, spotted occasionally with the tall trunk of a canal cactus, rising above it. Later he would see infrequent dome farms, but he could expect no more than two or three score of these in the entire long drive to Hesperidum. Dark slowed and entered the cloverleaf that took him onto the bypass expressway. Even as he did so, the radio crackled and the thin voice of the Chief sounded over the groundcar loudspeaker. "Attention, Phoenix," said the Chief intensely. "Attention, Phoenix. Emergency instructions. We have monitored reports that the government is checking airlocks at all cities. Repeat: the government is checking airlocks at all cities.