Lynne knew what he meant. On Earth, with its dense atmosphere and metallic atmosphere vapors telepathy was almost unknown. On Mars, where the air was thinner and purer, it flourished but other telekinetic powers were weak and incapable of being controlled. Here on Callisto, with no atmosphere save what was frozen solid underfoot, there was just a chance.... Perhaps, if they worked together, they could exert sufficient psychic power to turn the switch and put the super-entity out of its misery. _Why doesn’t it turn the_ FARBISH _thing off itself?_ Lynne telepathed. _Did you ever hear of any creature, however advanced, removing an alien object from its own brain?_ was the quick response. And somehow Lynne knew Rolf was right. It was going to be up to them. _We’ll have to keep cover behind the revetment_, she replied, _in case we fumble at first and our friend starts blasting again._ Rolf asked that they be left alone in the compression chamber for a bit. And there they practiced on small objects--a stencil-recorder, a gravity-weight, a set of earphones. It was the hardest kind of work but, even within the metal shell of the ship, they were able at first, by linking up in the tightest of combinations and willing as one, to move aimlessly, then to attain control over the objects and move them about at will, even to lift them briefly from the deck. Exhausted, they rested, sitting close together on the floor of the chamber, their backs against the wall. And Rolf said, “We’ve got to do a lot better before we can risk a real trial. If we’re wrong--or if we make a mistake....” He let it hang there. Lynne nodded. Like him, she was too mentally exhausted for telepathy. She said, “I wish I weren’t telepathic. I wish nobody were telepathic. Then none of this would have happened.” He nodded and told her, “I suppose Columbus wished he’d never tried to cross the Atlantic when his men threatened mutiny. I suppose Henry Condon felt the same way when his spaceship broke down on the first trip to the Moon. I _know_ we’ve all felt that way at times on Mars when things looked bad. But feeling that way isn’t going to save those poor devils upstairs. And it won’t get us off Callisto.” “I know,” she said with an attempt at a smile. “Let’s go on up and tell them we’re making progress.” As Rolf helped Lynne to her feet, he said, “Actually, you know, we’ve done amazingly well.” Lynne lost track of time as she and Rolf slept and practiced, slept and practiced, sheltered from the wrath of the strange entity beyond the rock revetment by the metal skin of the E.I.A. ship. At times, especially when she was tired or distracted, it seemed as if they were never going to master telekinesis at a distance. Staying in the ship, they were sorely limited. But they dared not test outside lest their efforts add to the entity’s irritation and cause it to strike back with renewed fury. They did not even dare risk another message to Mars.