It was Ned who discovered the mind block.
Not only had the Sweeneys ceased to age physically—they lacked a normal time sense. If you reminded them of the passing years their minds cleared momentarily, and they could think back.
But that link with the past had no staying power. It was like punching pillows to get them to remember. They lived in the present, well content to accept the world about them on a day-to-day basis, warmed by the bright flame of their children growing up—
But their children weren't growing up—they had only the illusion of change, the illusion of planning for their future; and that illusion was terribly real to them—unless jolted by a question:
"How's Tommy?"
"Why, Tommy hasn't changed at all—"
A puzzled frown. A moment's honest facing of the truth, an old memory stirring into life. Then the mind block closing in, clamping down.
"Ned, Cynthia, you'll stay for dinner?"
It was late and growing cold, and the stars had appeared in the sky. In the rocket-ship Ned sat facing his wife.