Hutchman opened his eyes. “Not from me, you wouldn’t.”

“Am I not your type, Hutch? Not intellectual enough?”

Hutchman glanced at the large varnished pebble he used for a paperweight and imagined smashing Spain’s head with it Plea: justifiable insecticide. “Get out of my office, Don — I have work to do.”

Spain sniffed, producing a glutinous click in the back of his nose, and went through into the connecting office, closing the door behind him. The gray abstract of his figure on the frosted glass hovered in the region of Muriel’s desk for a few minutes, accompanied by the sound of drawers being opened and papers riffled, then faded as he moved into his own room. Hutchman watched the pantomime with increasing self-disgust for the way in which he had never once come right out and told Spain what he thought of him. I can make neutrons dance to a new tune, but I shrink from telling a human tick to fasten onto someone else. He took a bulky file marked “secret” from the secure drawer of his desk and tried to concentrate on the project which was paying his salary.

Jack was a fairly conventional ground-to-air missile employing the simplest possible guidance-and-control system, that of radio command from the firing station. It was, in fact, a modification of an earlier Westfield defensive missile which had suffered from an ailment common to its breed — loss of control sensitivity as the distance between it and the launcher/control console complex increased. Westfield had conceived the idea of transferring part of the guidance-and-control system to a second missile — Jill — fired a fraction of a second later, which would follow Jack and relay data on its position relative to a moving target. The system was an attempt to preserve the simplicity of command-link guidance and yet obtain the accuracy of a fully automated targetseeking device. If it worked it would have a respectable range, high reliability, and low unit cost. As a senior mathematician with Westfield, Hutchman was ehgaged on rationalizing the maths, paring down the variables to a point where Jack and Jill could be directed by something not very different from a conventional firecontrol computer.