The ship was proof against any test, but the men inside her could be strained and warped, individually and horribly. Unfortunately, while the men knew that, they couldn't really believe it. The Aliens could--and did.

_They sent the advance unit out to scout the new planet in the _Ambassador_, homing down on the secret beeping of a featureless box dropped by an earlier survey party. Then they sat back at GHQ and began the same old pattern of worry that followed every advance unit._

_Not about the ship. The _Ambassador_ was a perfect machine, automatic, self-adjusting, self-regulating. It was built to last and do its job without failure under any and all conditions, as long as there was a universe around it. And it could not fail. There was no question about that._

_But an advance unit is composed of men. The factors of safety are indeterminable; the duplications of their internal mechanisms are conjectural, variable. The strength of the unit is the sum of the strengths of its members. The weakness of the unit can be a single small failing in a single man._

_Beep ... boop ..._

"Gotcha!" said Ives. Ives was Communications. He had quick eyes, quick hands. He was huge, almost gross, but graceful. "On the nose," he grinned, and turned up the volume.

_Beep ... boop ..._

"What else do you expect?" said Johnny. Johnny was the pilot--young, wide, flat. His movements were as controlled and decisive as those of the ship itself, in which he had an unshakeable faith. He slid into the bucket seat before the great master console.

_Beep ... boop ..._

"We expect the ship to do her job," said Hoskins, the Engineer. He was mild and deft, middle-aged, with a domed head and wide, light-blue eyes behind old fashioned spectacles. He shared Johnny's belief in the machine, but through understanding rather than through admiration. "But it's always good to see her do it."

_Beep ... boop ..._

"Beautiful," said Captain Anderson softly, and he may have been talking about the way the ship was homing in on the tiny, featureless box that Survey had dropped on the unexplored planet, or about the planet itself, or even about the smooth integration of his crew.

_Beep ... boop ..._

Paresi said nothing. He had eyebrows and nostrils as sensitive as a radarscope, and masked eyes of a luminous black. Faces and motives were to him what gauges and log-entries were to the Engineer. Paresi was the Doctor, and he had many a salve and many a splint for invisible ills. He saw everything and understood much. He leaned against the bulkhead, his gaze flicking from one to the other of the crew. Occasionally his small mustache twitched like the antennae of a cat watching a bird.

Barely audible, faint as the blue outline of a distant hill, hungry and lost as the half-heard cry of a banshee, came the thin sound of high atmosphere against the ship's hull.

An hour passed.