The automatic lock clicked off as the jet room returned to habitable conditions, and at Captain Reno's gesture two men swung the door open. Quickly the commander entered the blasted jet room. Barry Barr was close behind him.

Robson Hind, jet chief of Four and electronics expert for Venus Colony, hung back until others had gone in first. His handsome, heavy face had lost its usual ruddiness.

Captain Reno surveyed the havoc. Young Ryan's body floated eerily in the zero gravity, charred into instant death by the back-blast. The line accelerator was a shapeless ruin, but except for broken meter glasses and scorched control handles other mechanical damage appeared minor. They had been lucky.

"Turnover starts in six hours twelve minutes," the captain said meaningfully.

Robson Hind cleared his throat. "We can change accelerators in two hours," he declared. With a quick reassumption of authority he began to order his crew into action.

It took nearer three hours than two to change accelerators despite Hind's shouted orders.

At last the job was completed. Hind made a final check, floated over to the control panel and started the fuel feed. With a confident smile he threw in the accelerator switch.

The meter needles climbed, soared past the red lines without pausing, and just in time to prevent a second blowback, Hind cut the power.

"There's metal in the field!" His voice was high and unsteady.