They moved down the ramp. Craig stopped breathing again as a voice from the ship's intercom system shouted from the lock behind them.
The voice was an excellent imitation of Captain Martin. It spoke with crisp authority and with sureness. It was a commanding voice. It caught the attention of its hearers.
Captain Martin seemed to freeze on the ramp. Suddenly sensing what was about to happen, Craig Randall also froze. The voice came again.
"Attention, all hands! Attention, all Pluto Station men on board the _Andromeda_! A dangerous situation has been discovered in the drive room of the ship. You are hereby directed to clear the _Andromeda_ instantly. A delay of a few seconds may mean the difference between life and death."
The voice gained in volume, became more commanding.
In the seconds that elapsed while the voice was rolling from the ship's communication system, Craig grasped what was going to happen next, and what he was going to have to do about it.
Captain Martin spun back toward the open lock.
With all his strength, Craig slugged the captain on the side of the jaw. The blow knocked Martin sideways and down to the ramp.
But it did not knock him out. Snarling, he came to his feet. Craig he ignored, the man who had slugged him was not important to him at this moment. Cursing, he started toward the open lock. Craig tackled him around the legs. The captain fell heavily. Craig rolled with him to the edge of the ramp, forced him over it. Both fell to the hard floor of the vast hangar.
In obedience to the voice that had come over the intercom system, and which had sounded very much like the voice of Captain Martin, men were already pouring from the lock.
Beside the ramp, Craig and Captain Martin fought viciously.
In the captain's cabin, Nuoy heard the voice. He snapped open the communication line between this cabin and the control room.
"What nonsense is this?" he shouted into the mike. "There is no way a dangerous condition can develop in the drive of these ships!" He was speaking the truth. Deep-space ships, all space ships, were hazard proof so far as the drive was concerned. He expected an evasive denial.
"Of course no dangerous condition can develop," the voice from the control room answered.