Reaching the foot of the main dome over the establishment, he glanced furtively about, then plunged his knife into the transparent material.
From the corner of his eye, he thought he saw Betty make a startled gesture, but he had his work cut out for him. This was tougher than the interior dome.
Finally, he managed to saw a ragged slit through which they could squeeze. There was room to walk between the inner and outer layer, so he moved along a few yards. A little dust began to blow about where they had gone through. He touched helmets once more.
"This time," he said, "the air will really start to blow, so get through as fast as you can. If I can slap this piece of plastic over the rip, it may stow down the loss of pressure enough to give us quite a lead before the alarms go off."
Through the faceplates, he saw the girl nod, wide-eyed.
As soon as he plunged the knife into the outer layer, he could see dusty, moist air puffing out into the near-vacuum of Ganymede's surface. Fumbling, he cut as fast as he could and shoved Betty through the small opening.
Squeezing through in his turn, he left one arm inside to spread the plastic sheet as best he could. The internal air pressure slapped it against the inside of the dome as if glued, although it immediately showed an alarming tendency to balloon through the ruptured spot.
They'll find it, all right, Tolliver reminded himself. Don't be here when they do!
He grabbed Betty by the wrist of her spacesuit and headed for the nearest outcropping of rock.
It promptly developed that she had something to learn about running on ice in such low gravity. Until they were out of direct line of sight from the settlement, Tolliver simply dragged her.