He added almost ferociously: “The trouble is, I don’t know enough. I’m trying to build too high without scaffolding….”

* * * * *

After that day at Cambridge I thought I was bound to have crossed some sort of barrier, and that henceforth I could count on seeing him fairly regularly, either at the College or at the house; but in fact a rather long interval elapsed, so that I stopped Mathews once and asked how Brad was. He said he was wearing himself out as usual, or rather more than usual—indeed, he’d given up one of his teaching classes in order to devote more time to his own work.

“Can he afford that?”

“Evidently. Or else he’s making himself afford it.”

“Do you know what work it is?”

“Vaguely. Some sort of mathematics. But you can’t know much about other people’s work nowadays, not when they get past the elementary stage. Even genetics has its mysteries. Why don’t you come and see my mice? I don’t have cats any more—they’re not quick enough on the job. And besides, they’re apt to attract visitors.” He always joked about my mother’s acquisition.

I went up with him. “I wouldn’t disturb him while he’s busy,” he said, as we passed Brad’s door. I hadn’t had any such intention, but the warning made me ask what special reason there was for all the high pressure.

He said he thought something had “happened” at Cambridge. “He goes to the Cavendish there fairly often. He told me after one trip that a physicist was no damned good unless he was also a mathematician, so that’s what he’s doing now, I suppose—in what he calls his spare time…. Come and see these creatures again when you feel like it. Perhaps he won’t be so busy.”

He was, and I didn’t bother him. But one afternoon, inside the College near the Physics Building, I met my mother walking along as if she had far more right to look surprised than I had. She asked if I were going up to see Brad. I replied: “Certainly not. Have you just been to see him?”

“Darling, why ‘certainly not’?”

“Because he hates to be interrupted when he’s at work. It’s a thing I’d never dream of doing…. But I suppose you have seen him?”

“Yes, but not in the way you think. I’ve been to one of his lectures.”

“What?”

“I don’t see any reason against it. He has a beginners’ class—anybody can join who enrolls. I’ve enrolled. It’s interesting. And he explains things so wonderfully. One ought to have something serious in life, oughtn’t one?”

“What does Brad say about it?”

“Brad?… yes … it suits him, doesn’t it?… Or perhaps it’s just that I never did like Mark and I couldn’t go on calling him Mr. Bradley—Dr. Bradley, I mean…. Anyhow, I think the less formal we all are the better. That’s what the trouble is with him—he’s too formal—he doesn’t seem to believe in any pleasure, amusement, relaxation…. But I have an idea I’m beginning to convert him—gradually.”

She looked so adorable as she said it that I laughed. “And he’s managing to convert you a little at the same time, eh?”

No, she answered, he was not converting her—not really.