Barely two minutes till grav-time now, the chronox said.
Krobis straightened. "You'll never get away with this, Boone!" His voice was thick with hate.
"Because you'll stop the grav-off, you mean?" Boone spun the nerve-gun's dial back to the temporary paralysis level. "I've thought of that, too, Krobis."
He squeezed the trigger.
The other's eyes went blank and glassy. He slumped beside Eileen on the ramp.
Pivoting, Boone strode back to the ship.
The hatchmen were already gathering with their sealers. The hum of the converters rose in an all-pervasive drone.
Up in the tech quarters once more, Boone wryly slipped the card bearing Eileen's name from its bracket on the door and substituted his own. Then, going on into the cabin, he threw himself down at full length on the foamex bunk. He was tired, more tired than he could remember ever having been, with the utter weariness that comes of too much strain and tension.
A moment later the signal light above the door flashed red. Then a momentary shifting said that the sphere was off the ground and rising, riding its great beam of anti-gravitational force up from Ganymede's bleak surface.
So it was done. Eileen was safe at last and he, Fred Boone, was on his way to Titan.