“We’re still not out of the woods,” Rock reminded him. “We’ve got to get you free.”

He went after the trapped foot with a more determined vengeance. Shep howled, but Rock finally jerked it free of the stubborn crevice.

When they reached the bottom, Shep was limping and said his ankle hurt. Rock supported him and they headed back toward the Northern Cross. They continued with caution, keeping out of the open as much as possible.

“I don’t see that we accomplished much,” Shep said wearily.

“It’s given me another plan, at least,” Rock replied, brushing at a new growth of ice crystals.

“Oh, oh, here we go again!” Shep sighed, then winced as his ankle hurt him again.

“All of us,” Rock began, “except you—if you’re not up to it—will come back over here. We’ve already proved that the trip can be made without their seeing us. We’ll station ourselves around the air lock, except for one who will climb the formation and kick rocks down again on the ship. This time Kalmus will be sure it’s us, and they’ll come out to investigate again. When they come out, our bunch will slip inside. If Judas has been left to watch Leo and Ed, he shouldn’t give us much trouble by himself if we slip up on him and catch him unawares. Once we’ve locked out the other three they’ll give in willingly just to get back inside.”

“That’s pretty daring,” Shep said doubtfully, “but I guess we’ve got to be daring if we’re going to save the boys.”

As they walked, Rock radioed the Northern Cross with the walkie-talkie he’d been carrying on his back, telling the boys of their close call.

When the two reached the ladder bridge across the rift, Shep had difficulty crossing with his injured foot. He went first, and as Rock steadied the frail bridge, he held his breath tensely for fear Shep would slip. They had used the safety rope again, but, if one of them should fall, he could easily rip open his suit as he thudded against the jagged side of the chasm.